


Curse of the Were-Tuna

by WhoGroovesOn



Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Alternate Universe, Anal Sex, Aquariums, Canon-Typical Violence, Cuddling, Curses, Drinking, F/F, First Time, Fish, Frottage, Hand Jobs, It's Not Crack I Swear, Kissing, London Aquarium, M/M, Magic, Nudity, Romance, Safer Sex, Sex, There is NO bestiality in this fic, Transformation, Tuna Sherlock Holmes, Were-Creatures, fem!Moran, fem!Moriarty, gill caressing, mild body horror, tuna with a scarf
Language: English
Status: Completed
Published: 2015-08-19
Updated: 2016-09-12
Packaged: 2018-04-15 12:45:02
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 9
Words: 46,916
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4607241
Author URL: https://archiveofourown.org/users/WhoGroovesOn/pseuds/WhoGroovesOn
Summary: <blockquote class="userstuff">
              <p>John couldn’t help but feel as though the large tuna beyond the glass was staring at him, which was weird because it’s not like fish had eyelids, they always seemed to be staring at things.</p>
            </blockquote>





	1. That Fish Is Staring At Me...

**Author's Note:**

> Thanks Nautilicious for betaing this strange little fic for me. :D

“Needed: Security guard - night shift”

John would take that! He needed the job. Invalided home, living in London on an army pension, he needed the work, needed the money, and if that meant night shift at the bloody London Aquarium he’d jump aboard that ship. Besides what was the worst that could happen at night in an aquarium? Oh, the octopus escaped again? Nemo’s been lost? Psh, lots of walking and sitting watching loads of fish and the odd sometimes not-fish things calmly swim about.

The moment John stepped out of the office with his shift hours and uniform he was met by a rather intimidating looking posh toff with an umbrella who promptly proceeded to pull him away into the depths of the aquarium.

“Do you know who Sherlock Holmes, is Dr Watson?” he asked, as he serenely strolled past a massive tank with a replica whale skeleton settled in the bottom. Children ran around everywhere and the place was in general a loud echoing room, forcing John to keep close to the aloof man just to hear him.

“No, should I?” John replied as they turned a corner and entered a glass tunnel, sharks and turtles and all sorts of fish flying above while children and parents ooh’d and aah’d at them. The man kept walking, avoiding the crowds of people until he rounded the corner and stopped in front of the aquarium’s pride and joy, the huge shark tank with Easter Island heads towering from the bottom of the tall tank. 

“No.” His fingers tapped on the handle of the umbrella in front of him.

“Sir-”

“Mycroft. Holmes,” the man corrected in clipped tones. “Sherlock Holmes was my younger sibling.”

“Mr Holmes, look, I don’t know what’s going on but if you could get to the point, I’ve got somewhere to be…” John trailed off as a huge fish swam by the window, not a toothy shark, one of the other ones swimming in schools throughout the tank. It darted past again before slowly drifting by. It was a large tuna fish… and John couldn’t help but feel as though it was staring at them, which was weird because it’s not like fish had eyelids, they always seemed to be staring at things.

“Some months ago my brother disappeared from this aquarium. His attacker was never found but it is assumed that they were… fish-napping, as it were, when he discovered their operations and pursued them.”

“And you would like me to keep an eye out for his killers?” John asked incredulously peeling his eyes away from the fish that had turned in a graceful arc to drift by again. This one looked different from the others too, it had larger dark markings that covered more of its body whereas the others were mostly silver with a black stripe on the back.

The elder Holmes simply hummed, twirling his umbrella handle under his palm, steel blue eyes following the fish as it darted away down into a faux rock corner of the tank. “An eye out would be adequate. Good day, Dr Watson,” he said before turning and walking away into the crowds of families still bustling through the halls. John was left to ponder the strange man for a moment before he decided to make his way through the rest of the aquarium and out; he took one last look at the unique tuna, drifting by on his lonesome, through the glass top down view of the tank near the exits.

_Where the hell is this water coming from?!_ John thought for the fourth night in a row since he’d begun night shift. It was always in the same place: behind the scenes in the shark tank upkeep area, a long trailing puddle of water down the hall leading out into the aquarium proper. No one was scheduled to be in this late at night and yet it always appeared as though a diver had just flopped out on the floor and failed to do any sort of clean up. 

When asked about it in the mornings, the various workers had no explanations and had found no leaks in the tanks that could have caused the puddles either.

John was replacing the mop from one of the well hidden ‘employees only’ closets when he saw a pale shape down the hall out of the corner of his eye. John quickly ducked behind a concrete coral display, peering around a brain coral at the lone figure. The lone naked figure who stood hunched with his arms around himself, illuminated by the light blue glow of the Easter Island shark tank. John crept closer to the man, using the fake ship wreckage as cover. The person sat down on a bench looking into the tank. _Great I’m going to have to wipe that down,_ John thought as the pale white buttocks plopped down on the concrete seat.

“... clothes got picked up by lost n’ found again,” John heard the man grumble, his deep baritone carrying even as it roughened with a cough at the end. He quickly slunk forward to move behind the nude man. 

John dove on him, throwing him from the bench to the floor and attempting to pin him. When he tried to grab the guy’s wrists to twist them behind his back, however, they slid out of his hands as though greased. Using this to his advantage, the very tall stranger pushed and bucked John off, turning over and taking a swing at him with a large fist. They grappled together on the floor for a moment, John catching his wrists individually and trying to pin the larger man and gain control by sitting on his bare stomach. The man suddenly turned his hands in John’s grip and pulled, leaning up quickly to headbut John hard. Dazed, John was flung off and the man scrambled to get up, squirming away as John clutched his face. John reached blindly and grabbed a slick ankle, getting enough purchase on the large foot to bring the man crashing face first back to the concrete with a wet slap. John hastily straddled the guy’s back again and pinned both wrists to the floor.

“I am detaining you for- wuh!” John was suddenly tossed off and found himself pinned with the bigger man straddling him.

John stopped struggling the moment he got a good look at the man’s face, long and far too pale with a very faint silvery sheen to his skin, under a wet, curly mop of dark hair. His ice blue eyes were wide, staring down at John as he panted, searching, studying him. It was his neck that made John freeze: there were gills open on both sides of the man’s neck, honest to god gills flexing with every breath. John’s eyes widened.

“What the--” was about all he got out before the man swiftly raised one of John’s wrists to his mouth and bit him just hard enough to draw blood. John screamed as the lunatic vaulted to standing and proceeded to run while John cradled his bloodied wrist. John levered himself up and ran on shaky legs to find the first aid kit. After properly washing, disinfecting and wrapping the wound John set out to find the crazy nude bitey man running loose in the aquarium, but he saw neither hide nor hair of him for the rest of the night. 

As morning came a splitting headache began to bloom behind John’s eyes, running down his spine and permeating into a full body ache. He was making another round searching for the gilly man, beginning to wonder if he was going insane and had just imagined the gills when the tall nutter appeared again, decidedly less naked and dressed in a pair of neon blue swim trunks covered in clownfish and a yellow tank top with a cartoon otter and ‘Sea Life London Aquarium’ on the front. He was typing away at a computer meant for one of the children’s games.

The man saw John coming this time and quickly closed whatever he was working on, checking a little plastic fish watch on his wrist before darting away.

“Oi! Come back!” John shouted, running after the tall man. He had looped back into the aquarium, heading towards where John had found him the night before. The headache pounding in John’s skull only increased with the exertion of trying to keep up with those long legs. Adrenaline was pumping as he watched the man slide around a corner into a niche that dead-ended with a door to the staff only areas next to the shark exhibit. Unfortunately John had forgotten to re-lock that door after cleaning up the water so the man was already beyond it when John rounded the corner, breathing hard. Through the door he saw the pale man beginning to strip out of the stolen clothes, whipping the top off as he climbed the metal grated stairs going up to the tank. 

John bustled through the door after him and was halfway up the stairs when an extremely sharp pain stabbed through his back; he fell on the stairs crying out in agony. He looked up through watering eyes to see a pale figure peering down at him over the railing, naked as the day he was born, again. _Oh god--_ John thought that it suddenly felt very much like he was dying; the pain was everywhere all at once and it left him gasping into the rough metal grating of the steps. He was reaching for his phone to dial 999 when another stabbing spasm rocked him and the phone slipped from his fingers, clattering away. 

He gasped for breath, a feeling like razorwire cinched around his throat became more and more terrifyingly apparent over all the other pains, which were beginning to rival the time he’d been shot in the war.

John felt hands rolling and lifting his shoulders, dragging his feet up the stairs and laying him out on the cool concrete beside the pool. _The gilly man!_ He bent over John, putting his unexpectedly dry hands on John’s face and neck, John felt thin fingers sink into the sides of his neck and panicked. It felt as though they sank into an open gash. John was gasping and sobbing for breath, feeling his eyes bulge. The man quickly started to strip off John’s uniform, his button-up peeled away like John’s skin was slimy. John wanted to struggle and get away from the madman but the amount of pain paralyzed him. Once he had John naked he pulled the slightly bloody wrapping from John’s bitten wrist. The man picked him up again, this time in a bridal carry, and John began to thrash in earnest as he realized where the guy was taking him: towards the water of the shark tank. _The Killer! My wrist! He’s going to feed me to the sharks!_ John thought, trying to coordinate his limbs enough to get away.

John was unceremoniously dumped in the water, liquid instantly flooding his open mouth. He coughed and sputtered, flailing at the surface trying to find an edge to cling to. A large hand met the top of his head and pushed him back under; the man was drowning him! John flailed, pushing against the restraining hand, reaching for enough air for even a small breath, but to no avail. He felt his limbs go tingly, then numb, and he sank like a stone, water filling his lungs. He saw grey and silver shapes float past and the muffled sound of a loud splash nearby. John shut his eyes and accepted his death, somewhat thankful he wouldn’t be alive to feel the shark’s teeth. 

But he didn’t die. Moments passed where he floated, his eyes opened to blurry blue and black shapes. When he went to blink again he found that he couldn’t. Instead, the blurry shapes began to gain clarity as if someone had slipped a pair of goggles over his eyes and drained the water from them. A fish bumped him and he rolled, the pain gone and replaced by the instinct to swim and try to go upwards. But he was stuck, he couldn’t feel his limbs. 

The fish bumped him again pushing him up against the wall this time. It was the dark-colored tuna that lived in the tank. He hadn’t seen it since the day he started, not that he’d really been specifically looking for it. It had him pressed against the light blue wall with its massive barrel of a body. But the view was strange and distorted, bubbled out like he was looking through those fisheye lenses he’d seen in movies. The fish slid along his body till its large silver eye came even with John’s head. It pushed him again. Then he saw it: another large thin tail right behind him. He tried to spin to see the other fish pushing at him but saw nothing, just continued to float in a circle under the water with the tail staying in the same place at the edge of his vision. It then occurred to him to turn the other direction and catch it that way, but when he did it moved too, staying right there on the periphery. He’d gotten away from the wall and was disorientedly turning in space until that darker tuna appeared again and started pushing at the tail. _Oh good it’s getting it away from me,_ John thought. But no, when the tuna pushed at the tail John spun with it… like it was attached.

John felt a hysterical panic begin to rise as the thought occurred to him. He tried to bend and twist his spine further to see the tail better, maybe see what it attached to. He bent his spine almost into a perfect C shape only to see the tail connected to a fish body. _Oh god, oh god, oh god, OH GOD!_ The tail flicked and he was pushed out into the open water of the tank, above the statues on its floor. _Oh fucking bollocks, this isn’t real! This isn’t real!_ John tried reasoning with himself, _the killer just knocked me out and I’m asleep, asleep in the hallway with a massive goose egg and this is a dream!_ But it wasn’t. The more he struggled to wake up the more the tail propelled him around the tank, bumping into smooth walls of glass and concrete and scraping along them, the tail flickering away at the corner of his bubbled vision. 

_No! THIS ISN’T REAL!!_ He thought if he rammed himself into something maybe that’d wake him up, like a bomb exploding or a long fall jolted him out before. He tried flicking the tail faster, swimming at a glass panel in the opposite wall, but was intercepted by the dark colored tuna bumping into him. He floated there in the water becoming increasingly aware of his new body, of gills filtering water and the tail flexing, pushing him along. 

God, he wanted to cry. _What the fuck is this? Why won’t I wake up? Christ, am I in a coma somewhere and this is my fucked-up dream because of that skinny nudist?_ He just floated there, the normally beautiful surroundings of the tank he’d seen from behind glass a distorted nightmare that he could not even blink away. The other tuna stayed close by, bumping into him now and then, causing him to slowly spiral through the tank. 

It was the first hints of noise that startled John out of his panicked stupor. Looking to the glass he could see people moving beyond it, shadows of children and adults pressed up to the glass looking in. For a brief moment John struggled for cover. _I’m naked!_ he thought hysterically, trying to get his new body to work and get to the little rock hidey holes at the bottom of the tank. The same tuna who kept nudging him kept forcing him back upwards though, and John didn’t have enough control of his body to resist. Eventually he realized that fish don’t really need clothes exactly, and went back to floating and getting bumped by the one dark tuna as well as the other more mobile fish and sharks who couldn’t give a toss he was there. 

The people were terrifying once there were enough of them outside. He couldn’t make out what they were saying through the water, just a garbled monstrous low babble, and then a child would bang on the glass he’d managed to drift near and the reverberating sound through the thick acrylic would startle him into movement until he realized where it came from and went back to his listless nightmare.

Eventually the dark tuna started pushing him rather insistently towards a specific window until his side was practically pressed against it. That’s when he saw it: Mycroft Holmes sitting on the bench near the glass, newspaper open. He glanced up at John and the tuna behind him with raised eyebrows, his eyes flicking to the strange tuna first then back to John. He flicked the paper closed and stepped up to the glass, peering hard at John before he pulled out his mobile and began to make a call, his voice too quiet and low for John to hear anything of the conversation. He gave the dark tuna one more appraising look before he turned and walked away, brolly in hand, leaving the paper on the bench. 

Time passed. For John there was a moment of horrific embarrassment when his fish body decided to defecate; that was the one time the other tuna let him flee and hide in a corner of the tank for a while. John felt completely horrified by the fact that his body had just relieved itself in front of hundreds of onlooking people. 

He stayed there for an immeasurable amount of time, floating between a rock and the wall trying to stay away from prying eyes. Food did rain down at some point and John ate none of it, the other actual fish gobbling up squid parts and pellets perfectly happily. 

The noises from the people began to die eventually, the kids banging on the glass stopped and he continued to drift. Until the dark tuna came back and started pushing him again. When the slightly bigger fish pushed him out of his hiding spot John became more aware of his limbs. A sharp stabbing pain made him curl in on himself and instead of the bow of a tail he could actually curl in on himself, his arms and legs were back! He was completely naked and human again and breathing. He brought a hand to his neck, the slices of gills on either side of his throat opened and closed, still filtering away. 

He quickly kicked upwards, swimming for the surface. The tuna that had been prodding at him all day was nowhere in sight. Before he even reached the surface, let alone break it, a long arm darted into the water and grabbed him by the bicep, pulling him swiftly the rest of the way out. 

The moment he hit dry air his lungs burned and he began coughing, feeling like he was suffocating. The man attached to the arm hauled him out of the water and up onto the concrete, quickly pushing him onto his hands and knees. John’s body suddenly heaved and he retched an ungodly amount of water and bile onto the floor. He couldn’t see out of the water, his vision extremely blurry. Even as he continued hacking up water he felt hands on his face, thumbs and fingers rubbing and plucking at his eyes until finally something gave way and it felt like a thick skin had peeled away, clearing his sight perfectly out of one then both eyes. He felt slimy, like there was a gel film on his skin. John finally stopped retching but his entire chest felt sore. His limbs felt weak and his arms promptly decided to fold under his weight. Pale arms caught him before he could land face first in his own sick and pulled him to the side. John’s slime-covered skin allowed him to be pulled across the smooth floor easily. John looked up at the man hauling him with his hands under John’s armpits. It was the nude man from before. 

John immediately wanted away from him, wanted to scream at him, but weak as he was he could barely lift a hand to try to swat him away. He let out a wet gurgle when he tried to speak. Then he realized the man was talking, he just couldn’t hear it. John was laid down again and the man’s hands went to his head. The peeling sensation he’d felt with is eyes happened over his ears and a small dribble of water ran out as his hearing returned. He heard a sharp clacking noise hit the floor nearby and turned his head towards it.

“Sherlock, how did this happen?” Mycroft stood against the railing, keeping his pristine shoes far away from the mess John had just created. He looked none too happy as he leveled his stern gaze on the man still peeling off whatever was covering John’s other ear.

“Sherl?” John croaked out, trying to push himself away from the dark-haired man once his other ear was freed, only succeeding in having his palms slip out from under him and leave him lying on the floor. 

John weakly lay on his side for a moment. He heard the click of that infernal umbrella coming a few steps closer. A towel dropped unceremoniously onto his hip, providing some small amount of modesty, and when next he cracked open his eyes it was to a blurry view of Mycroft standing over him. “Dr Watson, you have, under extraordinarily poor circumstances, now met my younger brother, Sherlock Holmes.”


	2. This Prison Has a Lot of Fish In It

**Notes for the Chapter:**

> Thank you so much Nautilicious for being my beta.

“Sher-Sherlock Holmes?” John questioned, glancing up at the other man above him. Sherlock was peeling off what remained of something that looked like a clear jelly lens over one eye, tossing the bits of goo back into the water where fish were nibbling at perceived food.

“Yes, now would you kindly inform me what happened last night, since my brother isn’t divulging himself.” Mycroft stepped back a pace or two as John attempted to sit up again, rubbing slick hands over his face, before looking down at his now slightly webbed fingers.

“What happened?!” John looked up sharply at Mycroft. “I spent the entire day today as a bloody fucking fish! A fish, in my birthday suit, in front of a ton of strangers banging on the glass and watching me shit myself!” John yelled, his voice echoing with an unpleasant sort of ring off the bare concrete and piping. 

“Dr Watson, you’re becoming hysterical,” Mycroft said in the same calm flat voice.

“You try staying calm after going through that, no warning, just suddenly I feel like I’m having a heart attack, your brother dumps me in a fish tank, that contains sharks by the way, and I’m a fish for… fuck what’s the time?” John paused in his ranting, suddenly realizing he hadn’t a clue what time it was.

“Nine o’ clock,” Mycroft filled in, slipping a watch back into his waistcoat pocket.

“About fifteen hours!” John said doing the math quickly as his anger flared again, “And then there’s this mess. I have gills!” John cried, reaching up and plucking at the thin protrusions and flaps at the sides of his neck. “And before that your damn brother bit me and made me chase him through the bloody aquarium!” John looked down at the wrist that had carried the punctures from the bite to shove it at Mycroft, but the wrist was clean, only a small outline of silvery scars in the shape of human teeth marks left behind.

“Bit you?” Mycroft interrupted a single thin eyebrow raising sharply in Sherlock’s direction, the man not paying them any mind as he continued peeling things off his face and toweling himself dry of slime and water, still completely in the buff.

Sherlock looked up at his brother’s tone. “He attacked me.”

“I did not! I was trying to detain you, the naked man, in an aquarium, at night. How was I supposed to know you weren’t some nutter trying to skinny dip with the sharks?!” John flapped a hand at the water that they’d just come from as a pair of sharks graced the water surface with their ominous fins.

“I was looking for my clothes, by the way, Mycroft I need a locker. You have enough sway to keep me imprisoned here, the least you can do is reliably provide me with clothing,” Sherlock grumped.

“I told you your clothes were at the cleaners yesterday, you cannot expect to wear the same clothes for weeks on end, especially with… that all over.” Mycroft’s nose crinkled as he fluttered a hand at the mess the pair on the floor had left, John trying to scrub at it subtly while the brothers weren’t looking at him. “The assistant I had assigned to drop them off failed to do so and has been dismissed.”

“Wait, you knew about all of this?” John said pausing in wiping his face clean to look up at Mycroft again. “You told me he had disappeared.”

“Yes, and for all intents and purposes he has. A missing persons report was filed a week after his landlady began worrying when he didn’t return to his flat. He was never found, but his last whereabouts, according to the network of homeless people he uses for his work, were said to be at the aquarium,” Mycroft told him, looking down his pointed nose at John. “Upon further investigation and a few days monitoring CCTV footage around the premises I managed to finally spot my brother, bare as the day he was born, breaking _out_ of the building--”

“And then you made the place into a prison, heightened security and hired a barely competent excuse for a night guard. What are you? Afghanistan war vet with a shoulder injury? Yes, great job selecting this one, Mycroft. Meanwhile, I get to subsist off squid and fish pellets and anything I can scrounge from the snack carts at night,” Sherlock sneered at the both of them, before putting the towel over his head and vigorously scrubbing at his hair with the sodden thing.

“You don’t have to eat the squid and pellets--” Mycroft began, just as John spoke.

“I’m a doctor,” he ignored the way Mycroft looked down at him, “and a damn good one before I was invalided home. I nearly got you pinned, if you hadn’t bitten me, you mad bastard,” John said grumpily, still trying to cover himself and scrub with the edge of the towel at the same time.

“And you,” John pointed at Mycroft, “you could have at least told me to expect to see him around, at least lie and tell me ‘hey, my odd brother likes to go swimming in the tanks,’ maybe, I don’t know, pay me a little more to keep quiet about it and no one’s the wiser?”

“You wouldn’t have taken that any more that you would have taken the actual truth. Sherlock is usually rather stealthy about his goings on here. Had my assistant not failed to provide him his clothing for the night you might not have even seen him, or would have thought him a regular employee here,” Mycroft reasoned. John took in a massive breath, feeling air pass over gills as he sighed. It felt extremely strange. 

“Tell me you at least have some clothes for me,” John ground out.

“Of course, just down the stairs here.” Mycroft indicated with his umbrella. “Now if you are quite finished with your ranting, I have some business to attend to. I will leave you in the care of my brother. He should be able to teach you the ropes, as it were.” And with that he was down the stairs. John scrambled after him, bracing himself against the safety railing while looking down at the besuited arse.

“Wait a damn minute, you can’t honestly mean to leave me here?!” John shouted down at him.

“For the time being, yes. They do not make tanks to accommodate large tuna fish just anywhere and I would rather not have to scrape your flailing carcass off the London streets when you turn again in the morning. So here you will stay until my brother can solve the mystery of your transformations.” Mycroft’s eyes shifted to Sherlock, who had come to stand next to John just as naked as before. When John looked back Mycroft was gone, the slow pneumatic closing of the door the only indicator that the man had been standing there at all.

John grabbed his hair and groaned a miserable noise, “Shit.”

“I’m just as displeased by our current situation as you are,” he heard Sherlock say, the man already descending the stairs towards the pile of clothes set on a shelf.

“ _Displeased_?” John squawked at him, “This is not ‘displeased,’ Sherlock Holmes, this is far beyond that, there isn’t even a word to describe this I think.” John tried to scrub himself down quickly now that the brothers weren’t there to see him.

“At least you are awake and aware--” Sherlock said, slipping into a pair of slim black boxer briefs.

“Oh yes, just a wonderful experience,” John replied sarcastically, wrapping his towel around himself for some amount of modesty as he followed Sherlock down the stairs.

“You could have been stuck like that for three weeks and have absolutely zero clue how you got that way when you turned back,” Sherlock finished, glaring at John before he pulled on his trousers and toed on a pair of comfortable-looking trainers. 

That pronouncement gave John pause. He’d just been a fish for a day and it had seemed hellish. “What happened?” John asked quietly, slipping on a t-shirt. The clothes Mycroft had left weren’t remotely meant for going outside, more comfortable wear, pyjama trousers and t-shirts and a pair of crocs, loungewear at best.

“The memories are hazy,” Sherlock replied solemnly, “All I remember is waking up at the bottom of the tank and breathing. I struggled to the top and stumbled around until I managed to clear my eyes and ears. Left a trail of slimy footprints all the way to the doors, Mycroft was furious when he found me. He took me back to his home and I nearly died the next morning when I turned into a great big bluefin tuna fish on his kitchen floor.” Sherlock smirked at the memory even though it didn’t sound remotely funny.

“But what about before that? Why were you at the Aquarium to begin with?” John asked. Sherlock huffed a frustrated grumble. 

“Walk with me,” Sherlock demanded, walking away, not even looking back to see if John followed him. John did follow though, no reason to stay in the reverberating concrete halls alone. His knees were still a little wobbly as he walked, like coming off a boat after hours of keeping balance on it. 

Sherlock led him through the hall back towards the whale skeleton tank and took a seat on the step in front of the glass in the tunnel, propping his feet up on the step opposite. John followed his lead and took a seat next to Sherlock’s feet. One of the massive turtles in the tank passed overhead casting a shadow over the both of them briefly.

“I’m sure my brother has already told you that I am a consulting detective for New Scotland Yard?”

“Yes, I googled you after he mentioned you, Mycroft didn’t say much other than you were investigating some kind of fish stealing gang.” John replied, distractedly plucking at the short bits of webbing between his fingers.

“There’ve been a number of animals gone missing here, the curious part is that sometimes they come back. That turtle above us disappeared for a month, only to reappear completely unharmed. Others never return, two of their sharks have permanently gone missing along with a sea turtle that wasn’t on display, a Napoleon fish, a red tail catfish, and a stingray. All very large specimens. I was called in by a client who works here to try and find where the fish were going.” Sherlock looked up at the stingray gliding along the glass above. John watched his whole face scrunch like he was trying to remember something with all his might, his nose crinkled, his forehead creased, his lips thinned.

“I remember a blue glow, and long black hair, and a book. I think the glow was coming from it. There was a woman with the long hair, she turned around. She had very dark eyes. She wasn’t alone. And then someone clocked me over the head and I woke up underwater.” Sherlock’s face relaxed again and he sighed, “It’s very blurry. Every once in awhile a little more comes back, but not much.”

“Huh,” John said, not really having much to add, “Well… I guess I can’t stay mad at you, you didn’t exactly ask for this either, and we’re sort of stuck here till we figure this out.” John absentmindedly put his hand down on Sherlock’s calf, rubbing his shin through the pyjama bottoms. 

“We?” Sherlock asked. 

“Well I’m stuck here too, and I’d rather not spend the rest of my life inside an aquarium, so yeah the two of us together are going to figure this out.”

“Ah yes, you’re an outdoors sort of person,” Sherlock murmured.

“And what makes you say that?” John asked, raising an eyebrow.

“You have a tan, you’ve been home from Afghanistan for what? A few months to a year. If you were the indoors type that tan would have faded ages ago.”

“Well, I’m a doctor, a lot of the work I did was indoors, how can you be so sure I don’t go to a tanning bed?” John asked with a small smile of his own.

Sherlock rolled his eyes, “I’ve seen your arse, your ankles, and your scar. You have tan lines from your pants and your shoes and your head, neck, and forearms have a slightly darker tan than the rest of you. No idiot wears their clothes to a tanning bed, and you don’t seem the type to use one anyway, _Doctor_.” Sherlock put emphasis on the doctor title.

“That’s quite brilliant actually,” John said, once Sherlock was done. Sherlock looked down at him at that.

“You think that’s brilliant?” he asked, sounding mildly stunned.

“Of course.” At that moment John’s stomach gave a loud gurgle and he wrapped his arms around his middle. “God I’m starving,” he moaned. 

“The McDonald’s next to the exit is open for another half hour. If you’re willing to throw on a scarf and pretend to be homeless we might get something there,” Sherlock said indicating down the tunnel where they’d come from. John heard Sherlock’s stomach give a sympathetic little grumble as well.

“Anything else?” John asked, hoping for something better but not expecting much.

“Nope,” Sherlock popped the P in the word. “Only things otherwise are snackbar food near the penguins and picking the locks on the soda and snacks in the gift shop. We’d have to leave the building for anything better. Once I came to my senses and was aware of being a fish I gave in and started eating the fish food, at least it’s nutritious,” Sherlock said, his mouth pulling in a moue of disgust.

John sighed. “Fine, fast food is better than none at all.” 

A couple scarves from the gift shop and few odd looks from the employees behind the counter later, John was already wolfing down a container of salty fries with a content sigh as they walked back through the aquarium. 

They ended up settling in for their meal in the rainforest area, Sherlock deciding to plop down on the squishy moss-textured flooring near the four-eyed fish, who just continued to putter around the surface of their tank unperturbed. They both tucked into their food, even though John did notice that Sherlock ordered barely a quarter of what he did. _Perhaps the squid bits are actually good for something,_ John thought, chewing on his burger.

“You were messing around with one of the computers this morning, before I turned into a fish. What were you doing?” John asked, the nearby info screen jogging his memory of that morning.

“Solving cases that do not require me being present to solve them, trying to keep myself from becoming so mind-numbingly bored here that I decide to leave and become a dying tuna at a crime scene, attempting to figure out what the hell makes me turn into a fish every day.” Sherlock replied dully. 

“What about the woman you remember?” John asked without really thinking.

“Oh yes John, let me consult my database of every woman with long dark hair who may or may not reside in London. Oh wait--”

“Yes I get it, I’m sorry I brought it up,” John interrupted before Sherlock could go further with his snark.

They resumed their meal and the only noise was the sound of the tank water and filters running around them. John finished his food with a content sigh, it may not have been all that healthy but at least it was filling and it meant he didn’t have to eat the pellets and squid.

“Oh god, I’m going to have to go through that feeling like I’m having a heart attack again aren’t I?” John said with a groan, suddenly remembering what turning into a fish had entailed last time.

“I doesn’t hurt that much after a couple turns,” Sherlock replied.

“How would you know? You didn’t even remember the first three weeks you were one,” John countered. 

“Because it doesn’t feel like much now, some twinges and disturbing pops and it’s done.” 

John still wasn’t looking forward to morning even with that reassurance. 

The rest of the night was spent mostly with John just watching Sherlock on the computer, little snippets of conversation happening off and on. John read over Sherlock’s shoulder a bit, fascinated by the cases Sherlock considered ‘less than a 7’ which was to say, ‘not worthy of my physical presence’. 

“So what happened to all your stuff? Mycroft mentioned a landlady earlier,” John asked.

“Mycroft has told her not to worry, I assume he’s used some form of cover story involving me being out of the country on business.”

“And this Detective Inspector Lestrade guy? You’re actually talking to him.”

“The same thing: I’m out of the country on important business for my brother, that explanation is enough,” Sherlock said, leaning back in his chair and giving a good long stretch.

“But what if we don’t find out how to fix this?” John asked after a short pause.

“I’ll figure it out.”

“Sherlock--” The beeping of an alarm came from one of Sherlock’s pockets, a plastic watch, the same one Sherlock had discarded the morning before. 

Sherlock made an annoyed groan and stood starting to walk swiftly in the direction of the shark tank, John following close behind.

“That didn’t feel very long,” John commented as Sherlock shucked out of his clothes, John mirroring him as he talked, trying to ignore the fact that he was once again naked next to Sherlock. “Are you sure it’s already morning?” The aquarium being completely underground with no windows did throw off John’s sense of time the first couple days he had worked there, he was willing to admit.

“Better to be in the water even if this cheap bit of plastic is off. Besides we have gills,” Sherlock said climbing the stairs up to the tank.

Sherlock slid right into the water and again John followed even though he could see the silhouettes of the sharks within. John felt a little dim to trust Sherlock so completely so quickly, but hell, when one has been turned into a tuna fish for a day one tends to throw that sort of caution to the wind and accept the fact that one’s only real means of stopping being a daytime tuna fish was to trust the only other man who has also experienced it.

In the water, John’s vision wasn’t as clear as when he was a fish but definitely clearer than when he had been ‘completely human.’ He saw Sherlock’s naked arse diving away from him, legs kicking with long slightly webbed toes fanned, gills open along his neck, flaccid cock bobbing in the water when he stopped to sit at the top of the Easter Island head with his legs crisscrossed. John shook his head and began to swim himself. The first breaths with the gills underwater were as strange as above it, if anything a little more disturbing, but he wasn’t yet a fish so he was fine with the bit of oddness. The both of them swam around amongst the other fish for a bit, Sherlock swimming circles around John with his long swimmerly legs and arms.

The twinge of the change was unwelcome when it came, considering John had been enjoying covertly admiring Sherlock’s arse. Another slightly harder twinge made John curl up on himself. The transformation this time certainly wasn’t ‘call an ambulance I’m having a heart attack’ worthy, but if he’d felt this at home John would certainly be contemplating going to hospital.

The next time John opened his eyes Sherlock was a fish. John’s vision had become infinitely clearer, which meant he unfortunately was a fish as well. The better vision allowed him to see a shadow move beyond the glass at the bottom of the tank. _There shouldn’t be any people in yet,_ John thought, tail propelling him towards the window. He swore he saw a human shape beyond it, but by the time he’d gotten good and close it was gone. _I’ll have to tell Sherlock tonight,_ he thought looking up at the larger tuna trolling along in circles up near the surface.


	3. Filet o' Fish

**Notes for the Chapter:**

> Thank you so much HiddenLacuna for betaing this chapter for me.

The next day passed in much the same fashion as that first day, only with decidedly less panicking. 

Becoming human again still wasn’t all that pleasant. John would hit the surface and start hacking immediately, then Sherlock would grab him by the arm and pull him up to the side of the tank where he could cough while Sherlock peeled off his jelly eye and ear caps. Sherlock was always the first out of the water; John didn’t know if that had anything to do with the fact that Sherlock had been a tuna longer, or if he’d just drifted off and couldn’t keep track of time as well as the detective did - maybe a bit of both. 

John completely forgot to tell Sherlock about the person he thought he’d seen; by the time he’d remembered he’d thought himself out of telling. Maybe an employee had gotten to work early, or Mycroft sent a minion to check if John had transformed again, or maybe he’d just been seeing things and there was no one at all. If he saw them again he’d bump Sherlock or something.

The second night with Sherlock, he seemed interested in what John was.

“You don’t look like me. Well, you are a tuna fish, but you’re not a _Thunnus thynnus_ ,” Sherlock had told him as they ate their burgers, John still with a bigger meal, having not yet given in to the allure of raw squid bits and pellets. At that moment Sherlock decided to jump up from his nuggets, which John questioned why he would even get considering how much the things looked like the fish food pellets.

“What’s that mean?” John asked, swallowing a fry.

“You’re not an Atlantic Bluefin, which is what I turn into every night. You have different markings.” The Detective scampered off to find the nearest accessible computer, and moments later John found him clicking his way through a fish database.

“Ah,” Sherlock hummed happily finding what he was looking for, “you’re a _Thunnus obesus_.” 

“A what?” That didn’t sound like a very flattering fish, to be honest.

“A Bigeye tuna. Slightly smaller than the bluefin, more of a game fish, you may have eaten one once in your travels - a plate of _ahi_ perhaps?” Sherlock said with a positively wicked grin.

“Oh wonderful, you’re some majestic giant of the sea and I’m the thing that gets served up with a side of chips,” John said. “Let us hope Mycroft doesn’t get hungry.”

“I am not, I’m an endangered overfished species,” Sherlock groused. “And besides, Mycroft wouldn’t eat you… although,” Sherlock looked at him slyly, like he was trying to hold in the biggest smile, “maybe he’d sell you to an excellent sushi chef.” He snickered at that, and John gave him a small smack on the arm.

“That’s not funny,” John said, looking over Sherlock’s shoulder at the picture of a bigeye tuna. He certainly was more colorful than Sherlock was in fish form, with bright yellow streaking down the sides and a lighter blue on top. Sherlock was more black-blue and silver than John was, and of course, even as a fish, bigger.

The following week was spent learning about each other in a new way. John would sit nearby as Sherlock fussed with his selected computer of the night, but eventually Sherlock would become fed up with fruitless searching and go marching off for a sulk, and John would continue to follow him around until the detective, the admittedly incredibly bored detective, finally tossed himself down on a bench or a ledge. 

“Why don’t you tell me about your cases?” John asked, three days into Sherlock’s sulking. He had never really wondered what a fish in a strop looked like, but now he had an idea. Watching Sherlock dart around the tank for most of the day before coming to rest near the bottom, fins all tucked in and belly in the gravel, John nearly swore if a fish could frown, Sherlock would be doing so.

“Why would you care about those?” Sherlock mumbled, tucking the dressing gown he’d been provided for the night a little tighter around himself, squashing his cheek into the curve of the large round sill of the tank. 

“You’re interesting, I’ve seen bits of the ones you answer on your website. If the ones you solve without being there sound like that, the stories you must have involving the ones you decide to grace with your presence must be amazing.” John replied, sitting down next to Sherlock, their hips pressed together by the roundness of the window. John didn’t really care about the close contact - once he’d seen the man naked and as a fish for most of the day, he’d given up on modesty, much as Sherlock had.

“You’re just saying that cause you’re bored,” Sherlock said.

“A little bored, yeah, but it’s true that you are interesting, and I would like to learn more about my… tankmate,” John replied, just as a unicornfish poked its long nose around the corner and proceeded to stare Sherlock down, it seemed. There was a moment of silence, and John noticed Sherlock look briefly over at him a few more times as if contemplating whether he should share his cases. Sherlock let out a large sigh.

“Fine,” he mumbled, rolling over onto his back. John noticed Sherlock tuck his long, webbed, toes under John’s thigh and smiled as he leaned against the glass again, settling in for a story.

“I’d kill for a cigarette,” Sherlock said, not looking at John.

“You smoke?”

“Once, yes. I’ve been using nicotine patches for the last year or two. It’s a little hard to stick a patch to a fish though.” He sighed at that. “Ever since this hell started I’ve been wanting a smoke, but Mycroft will not give me anything including the patches, and technically it’s illegal to smoke indoors, one of those law things.” Sherlock sneered, scowling at the unicornfish still floating next to him, the fish choosing that moment to go darting away.

“How dare your brother care about your health,” John said with a small chuckle, receiving a not so venomous glare from Sherlock.

“Do you want to hear a case or not?” Sherlock huffed.

“It’s not like there’s much else to do,” John replied, with a smile to combat Sherlock’s dark mood.

John won out in the end. Sherlock began telling him about a case that had involved a homeless man found frozen to death on the front step of a shop in the middle of winter. Turned out the homeless man wasn’t homeless at all, but a rather wealthy banker who had been dressed in rags after being murdered and was placed there. Sherlock had been called in to help figure out who did it and why.

The stories continued on into the night, Sherlock going on from case to case, sharing the small details he had stored away all in his head. Sherlock seemed genuinely surprised when John interrupted his monologue with interested comments and marveling praise. 

The first time John spouted, “that’s incredible,” he saw Sherlock start and caught the confused look the detective shot him, but when Sherlock continued on without comment John just assumed he’d startled the detective out of the memory he seemed so wrapped up in telling. 

The second time though, when John said, “Amazing!” Sherlock paused.

“You know you do that out loud?” he asked.

“I can stop,” John replied.

“No, no.” Sherlock said quickly. “Where was I? Oh yes, the pollen residue on the brother’s coat sleeve…” And on he went, retelling the story of a serial killer gardener who killed his victims and then buried parts of them in his clients’ gardens. Apparently during the case Sherlock had uncovered another unrelated murder because a man had buried his girlfriend in a similar manner to that of the killer, but hadn’t followed the same pattern.

By the time the alarm to get back in the water went off, the pair of them had begun to share more personal stories, not much, but the beginnings of things. Like Sherlock’s landlady Mrs. Hudson, and how he met her, and John’s sister Harriet who came up in conversation because Sherlock deduced that he had a brother he was not very close to, no other family, and that was why no one seemed to be looking for him.

The beeping saved Sherlock from having to tell John what he and Mycroft had been like as children. He got up, stretched, and started walking towards their tank, completely avoiding John’s final questions of the night by simply ambling away.

“I’ll get you to tell me eventually,” John said, with his own sly grin as they disrobed.

Sherlock just huffed and slipped into the tank. John dove in after him, just missing the large guitarfish they shared the tank with as he broke the surface. They were a little closer to their changing time that morning, and only moments later John felt the twinges and pops Sherlock had warned him would become the norm. 

Sherlock often simply trolled around in wide circles at the top of the tank once he was a fish. John couldn’t begin to guess what went on in his head during the tuna hours of the day. Considering John usually drifted off into space and daydreamed until he bumped into something, goodness knew what the massive brain of the detective got up to. But this time Sherlock actually changed his pattern a bit, he started circling down more in the level John stayed around. He started bumping into John and then Sherlock started actually nudging him like he had on John’s first day as a fish, only now John pushed back. There was no real friction in the pushing, when John nudged back into Sherlock’s side he slipped past him.

It became a bit of a game for a while, John joining Sherlock in his circling and trying to bump each other off course. For such a large fish Sherlock was agile, of course he’d had more practice at being a fish, but John thought being a bit smaller would help him. The different activity did wonders for John’s normally listless mood. It wasn’t much, but at least it got him out of the daydream funk being stuck in the tank had been giving him.

John noticed someone staring at them late in the evening, before the aquarium closed. The crowds of parents and children were beginning to thin, but on the upper deck of the tank, looking down at them, was a woman. She’d been standing there watching the fish for much longer than anyone else seemed to, even the odd art student who came by with a sketch pad. She watched them like Mycroft did and John felt his skin crawl a bit when he realized it was the pair of tuna in the tank she seemed to have the most interest in. John abandoned Sherlock’s path to drift closer to the glass trying to get a better look at her. Maybe she was one of Mycroft’s people. 

From what John could see through the thick glass she wasn’t very tall, with long black hair, very pale skin, dark eyes, and she wore a suit. She just stood there watching the fish - no phone out taking pictures, no drawing pad sketching, no texting, no graduate school students taking notes for their ichthyological studies - just those creepily dark eyes staring and flicking between John and Sherlock in a tank full of other more interesting fish. When John came close to look at her, her eyes went to him and she studied him as he drifted by. Her gaze made him wish he had eyelids to blink with.

She did eventually leave, but not until after the tannoy warned that the Aquarium would soon be closing. In the meantime John quickly darted away and up to where Sherlock was drifting, nudging him and trying to get his attention to look over at the window. If Sherlock got the message John didn’t know it as he continued to drift until the time to change came.

“Sherlock, did you see that woman?” John asked once his lungs were clear.

“The one at the top window with the long hair? She’s been here before, seems to like the sharks - and me,” Sherlock replied, toweling his hair dry.

“She doesn’t give you any sort of creepy feeling?” John asked.

“John, the aquarium gets plenty of repeat visitors, there are at least a dozen other people I’ve seen multiple times over the course of my stay here. Most of them have children, all of them enjoy staring at this particular enclosure because it is both the central attraction of the aquarium and people seem to be oddly fascinated by sharks.” Sherlock shrugged and continued with his drying. “The fact that so many people come to gawk at us is in itself _creepy to me_ \- why should one more woman make a difference?”

“But what if she’s the one you remember, the one you said you saw before you became a fish?” John said. Sherlock hadn’t remembered any more to add to that memory in the last couple days, but John was still hopeful that maybe something would jog his memory and get him to remember what and who he saw.

“Even if it was her, what would there be for me to do about it when I am stuck as a tuna under glass? If it is her, what would be the point of her coming to observe me? To gloat over her victory? ‘ha ha, I have captured the famous Sherlock Holmes. Now I can watch his fishy arse any day that I want and know that he can do nothing about it.’ I doubt it.” Sherlock cackled, making John snicker at his suddenly witchy voice.

“Fine, fine, I give, I still don’t like it though.” John said, just as his stomach gave a large grumble.

“You really should at least give the pellets a try,” Sherlock said, hearing the squelchy sound.

“I’m not eating raw squid, Sherlock,” John groused, dry and beginning to get dressed.

Of course going to McDonald’s for dinner every night couldn’t have been good for either of the tuna men, but John didn’t even begin to imagine how bad that night’s trip would be.

The pair of them doned their scarves, covering their gills, and headed towards the exit where the fast food establishment sat next to the gaming arcade, still blaring away with its lights and prize machines out front. There was almost no one in the McDonald’s beyond the employees when John and Sherlock arrived. The young woman who always worked behind the counter greeted them with a kind smile and took their orders as usual. 

Sherlock stood off to the side waiting for their meals while John got the drinks. Suddenly there was an arm around his neck, and the drinks in John’s hands flew up, and then down, and covered both him and his attacker in sticky fountain soda. John flailed for purchase as the large arm cinched around his neck and pulled him backwards. A large hand tried to clap a piece of cloth over John’s face but John quickly elbowed the man in the gut, ducking away from the sickly sour smelling thing.

He heard a cry from over near the counters and saw that there was another big brutish looking man putting the same moves on Sherlock, a white cloth shoved to the detective’s nose. John had no time to help Sherlock as his own thug chose that moment to come at him again - only this time John was ready for him. He grabbed the man’s wrist and used his own bulk against him, bringing the attacker into the ground. John instantly pinned the man, twisting his arms and holding his wrists with one hand and slamming his head into the floor hard enough to render the brute unconscious.

John heard Sherlock still struggling with the other man and looked to the restaurant’s employees for help. Ducked behind the counter, both of the women at the registers were staring at them with wide eyes; the cooks in the back also seemed stunned by the sudden outburst.

“Watch him!” John ordered to one of the cashiers, getting her attention, “Watch this one!” John repeated, not waiting for her small nod before he lunged himself at the other man, who threw the rag at John, gripping onto Sherlock’s now limp form and producing a knife. John stopped the moment he saw the small blade press to Sherlock’s jaw.

“Okay… Okay what do you want?” John asked backing away, eyes locked on the little silver penknife. “Whatever you want, it’s not worth killing him for it.” 

“We want him… and you,” the man said thickly, with a voice that sounded like he had a mouth full of gravel. The man’s face was pale and featured a broad pointed nose; when he spoke John noticed nearly all his teeth looked sharpened. Neither man wore masks or any kind of gear; they were both dressed simply in jeans and jackets with a burgundy scarf around the unconscious one’s neck, and a red tartan one on the one currently holding Sherlock hostage.

“He’s no good to you dead, then, is he?” John asked calmly, even though on the inside the adrenaline was telling him to jump and knock that knife far from Sherlock’s neck. “So how about you put the knife down.” 

“No. We need the both of you,” the tartan scarf brute grumbled at him, hiking Sherlock up in his arms more securely. “You’re gonna follow me.”

“What about your friend here?” John asked, nodding his head at Tartan Scarf’s knocked-out cohort. The man just grunted and shrugged.

“I have you both, don’t need him,” he said, starting to shuffle around John and towards the doors, the knife pressed to Sherlock’s cheek digging in slightly, opening a tiny red cut.

Tartan Scarf was abruptly pulled back towards the counters, grunting and choking as the scarf around his neck suddenly pulled tighter. One of the cooks had gotten brave and pulled the brute back by the ends of his scarf. Tartan Scarf flailed, dropping Sherlock straight away as well as his pen knife. He swung around and caught the young man across the face with a large fist, flattening the poor man instantly and causing one of the cashiers to gasp and try to drag him back behind the counter.

John took the opportunity to strike, using the same tactic the cook had to get Tartan Scarf to turn towards him again, pulling on the tails of his scarf, only this time the item of clothing was ripped out of his hands by the man pulling back and tearing the perceived weakness from his neck. It was John’s turn to gasp along with the other onlooking cashier - the man had gills, just like the ones John and Sherlock had covered. 

John could almost see it with more of the man’s pale skin uncovered - he was a shark. The paler blotches of a shark’s belly marked his throat and the underside of his chin, the broad nose became the point of a shark’s nose, and those teeth. John actually had to dodge them in that moment as the brute of a man dove for him, mouth open, and actually attempted to bite John’s nose off. 

John tried to grab for a weapon, coming up with a serving tray and bashing the shark man over the back of the head with it, the flimsy plastic not doing much and actually cracking after meeting the man’s thick skull. The man swung around on John and grabbed him by the throat, his scarf the only thing keeping the man’s fingers from sinking into his gills.

“You’re coming with us!” the sharky face growled at him. John continued to fight and struck out, a fist connecting hard with the broad nose in front of him. The man dropped John instantly. Crying out in pain, hands going to his face; the one punch had been enough to bloody the man’s nose. _Oh god, sharks’ weak spots are their noses!_ John remembered, staring down the enraged face focused back on him, thin trails of blood beginning at his nostrils. This time around, when the brute charged, he saw John’s fists coming and grappled with him, taking him to the floor. The breath rushed out of John as the bigger man landed on him still gripping his wrists. What the shark man didn’t see coming was John’s willingness to use his head. John quickly pulled his wrists back and brought his forehead up, headbutting the shark square between the eyes, with a satisfying crunch as John broke his nose. The man howled and released John’s wrists whereupon John struck out and delivered a final hard punch to the man’s face. 

The man fell to the floor in an unconscious pile right on top of John, who pushed the man over and instantly went to Sherlock, who was still completely out of it next to the counter.

“Please tell me someone called 999,” John said towards the counter where he knew the staff were still hiding.

“I did,” called the manager from the back. “Said they were on their way.”

John looked to the knocked out shark man on the floor, the gills on his neck still on display. _I need to call Mycroft, but I don’t have his number,_ John thought just as the one he’d knocked out first started to groan.

“Oh no you don’t,” John said scrambling over to the one that was starting to come to. He yanked the scarf from around the man’s neck and used it to tie his wrists behind his back, hoping that was enough to hold him. The first man bore similar features to his counterpart, the gills, the broad nose, the shark-ish teeth. 

John went to bind the other man, only to find the tartan scarf had been ripped to the point of unusability, so he pulled his own striped scarf off and used it instead. One of the cashiers gasped when they saw John’s neck.

“What’s wrong with your necks?” She asked, staring wide eyed at John from across the counter. John didn’t reply, just returned to Sherlock’s side, patting the detective’s face in a gentle attempt to bring him around.

John worried about what would happen to Sherlock and himself if they didn’t leave before the police arrived. Being unable to leave the aquarium, especially with the knowledge that someone out there wanted them, meant they couldn’t go to jail. Not unless the police really wanted an unpleasant fishy smelling surprise come morning. And Sherlock was not coming round; he still lay, limp, in John’s arms.

The next person to walk through the doors was not the one he expected. It was Mycroft, accompanied by a small handful of men all in black gear.

“S-Sir, this establishment is closing,” said one of the cashiers, emboldened by the sight of the black clad guards already beginning to haul away the shark pair, replacing the scarves with proper cuffs. 

Mycroft ignored her, stepping up to John and Sherlock, “I trust my brother is in good health,” he said to John, eyes surveying Sherlock’s limp but otherwise clean state, the small cut on his cheek the only bit of damage caused by the brutes.

“A couple of scratches, that’s all. Now what are you doing here?” John asked.

“I was alerted to an emergency call originating from a restaurant at the aquarium, the very one that you both dine at this time every night. The local CCTV cameras showed this rather shady pair entering the establishment. Considering my young brother’s penchant for dangerous circumstances, a visit was in order,” Mycroft replied, then he turned to the employees and the manager who had just come out front. “As for you, you all saw none of this, any damages done will be compensated, but otherwise if a word of this is breathed outside this restaurant I will know and you will be found out. You did not see this minor brawl, you did not see men with gills. You will continue to supply these two with whatever food they ask for and will not ask questions. Am I understood?” Mycroft’s voice had gained a steely dangerous edge to it, the kind that spoke of secrets and spy work and quiet killings in the night should there be any loose lips.

They all nodded quickly, the cooks meant to be in the back scuttling away. “Y-y-yes sir,” the cashiers up front replied.

“Now I believe these two gentlemen had an order they were waiting on, if you could please add an extra burger and fries to that, they will be on their way,” Mycroft told them voice turning almost saccharin sweet in an instant, even though the sweetness didn’t reach the rest of his face. “John, if you could pick up Sherlock.”

John looked at the detective still slumped against him in his lap and sighed. Anything to get Sherlock to a safer location. John carefully maneuvered Sherlock up to leaning against the counter and got him onto his shoulders in a fireman’s lift, not even close to dignified for the poor unconscious Sherlock but the easiest way for John to carry the long-limbed lanky man back through the aquarium.

“Mycroft, grab the food,” John grunted, carrying Sherlock like a sack of potatoes towards the door. “Please,” he added as an afterthought, and he heard the crunch of the paper bag being picked up behind him.

John found a comfortable bench in the rainforest zone near the children’s play area to set Sherlock down. The wide bench shaped like a log allowed him to prop Sherlock up in the corner of the little alcove. John turned to see Mycroft with his umbrella hooked over one arm and the large bag of food in his other hand. He could almost see Mycroft physically trying to hold the fast food with just a couple of fingers to keep the grease away. John rescued Mycroft from the grease, taking the food from him and setting it down near Sherlock’s feet.

“Are you going to tell me why those men had gills like us?” John asked Mycroft as the man was turning to leave.

“As much as it pains me to say it, I do not know,” Mycroft replied, looking a bit like he’d just swallowed a sour grape. “I will be interrogating them and return with more information… soon. In the meantime, stay inside the aquarium, and keep Sherlock safe,” he added, continuing on his way back towards the exit.

John watched him go for a moment. _Well that’s a little scary,_ John thought. Mycroft not knowing something and the fact that that pair of shark men wanted to take them to someone.

Sherlock groaned behind him and John abandoned all thoughts of the gilled men. Sherlock started awake suddenly, before clutching his head and going back down.

“What happened?” he asked groggily looking at John, who was hovering over him just in case Sherlock suffered any ill effects from the chloroform.

“We were attacked, you got chloroformed and passed out, I knocked the pair on their arses, Mycroft cleaned up the mess and just left.” John gave him the short version, getting the food so they could eat it while it was still warm. John knew Mycroft had ordered the extra food for Sherlock to eat, caring in his own way.

“Oh… Thank you,” Sherlock said, sitting up a little slower this time patting John on the shoulder. He slowly picked up a pack of fries to nibble on. “There’s more to that story, but at the moment I’m starving. Tell me more in a minute,” he added, still somewhat soft and loopy. 

John could tell that the detective’s laser focus was still trying to come back online and Sherlock was frustrated by it, but the gratitude over John protecting him was genuine and that made John’s heart swell a bit and a small smile appear at the corners of his mouth.

“Sure thing, Sherlock,” he replied picking up his own meal and digging in alongside him.


	4. Cuddle Fish

**Notes for the Chapter:**

> Thank you Nautilicious for being my beta on this silly fic. :)

John shared what happened while Sherlock was out cold after they finished eating. Sherlock was still a little groggy from the chloroform but otherwise paying attention.

“They were fish men, Sherlock! Like us with gills and all, only they looked a little more like fish than we do, with markings,” John repeated as Sherlock tilted his head back against the wall. He had his hand against his face massaging into his eyelids.

“Yes John I heard you,” he grumbled, dropping his hand to look up at the fake vines on the ceiling, “the question is now who sent them? Who made them? All this has done is give Mycroft another reason to keep us sequestered in here and we are still no closer to solving the mystery of who has done this… Though I now have an idea where two of the missing sharks may have gone, but considering this aquarium is not the only one that contains sharks and we have no idea how far their master’s reach is that pair could have literally come from anywhere.” Sherlock bumped his head back against the wall in frustration.

“Well at least it’s something,” John said, trying to lighten the mood.

Sherlock’s face remained a mask of upset for a little while longer before his chest rose in a massive sigh. “I guess you’re right John,” he said, looking to John tiredly.

They simply stared at each other for a long moment, gazes locked. Sherlock’s face had softened with his sigh and he attempted a small smile, the corners of his lips curving up and the little gesture actually meeting his eyes. John’s eyes drifted to the scratch on Sherlock’s cheek and he brought a hand up to cup the side of Sherlock’s face, thumb brushing just over the small cut. “We should probably get a bandage on that,” John murmured breaking the intimate silence between them.

“It’ll heal in the morning,” Sherlock said, John feeling his baritone rumble through the skin contact. Sherlock picked up John’s other wrist where it rested in John’s lap; he stroked a thumb over the pale bite mark shaped scars there. “Remember?” he said quietly.

John looked down at where Sherlock was brushing over the thin skin near his pulse point. He glanced up at Sherlock through his eyelashes to see those light blue eyes looking back, the smile still in place.

A massive yawn on Sherlock’s part broke the moment and caused John to chuckle before the contagious yawn caught him as well on a smaller scale.

“Apologies,” Sherlock said, scrubbing a hand over his face, dislodging John’s hand from his cheek. John could almost swear he saw a faint blush forming at the tops of those cheekbones.

“That spat over dinner took a bit out of us didn’t it?” John said good humoredly.

“You’re about to suggest a nap,” Sherlock replied.

“I was going to say we should rest tonight, but a nap sounds just fine as well.” John saw the little frown that accompanied a slight put-upon sigh and an eyeroll to complete the package. “Come to think of it I never see you sleep.”

“Because I sleep while I’m a fish so I might be awake through the night. You doze too, I’ve noticed.” Sherlock said, arching an eyebrow at John.

“It is rather boring being a fish,” John admitted, “but we could use a bit more sleep during the night time hours.” He added with his own ‘you know I’m right’ look thrown towards Sherlock’s raised eyebrow.

Sherlock let out another larger sigh and settled in, laying down a little more comfortably on the curve of the log bench. John smiled at him, thankful that Sherlock wasn’t putting up much of a fight, a testament to how tired he really must be feeling.

“There we go, now come here and we’re all set,” John said settling in beside Sherlock. He propped himself up against the wall a bit and pulled Sherlock’s head into his lap, the detective squirming a bit, readjusting himself with the top of his curly head pressed up into John’s belly and his cheek to his thigh, spine bowed and knees tucked up, one hand curling into the loose fabric of John’s pyjama trousers. John smiled down at the re-settled curly head, running his hand over it and playing with the curls. In no time at all Sherlock’s breathing began to even out and he fell asleep, a hand still clutched possessively to the fabric over John’s knee. 

John followed him a short time later, leaning over against the back wall of the dim alcove, still gently playing with Sherlock’s hair as he drifted away.

The both of them must have been much sleepier than they had thought. John was awakened by the sound of Sherlock’s alarm going off and for a brief moment he forgot where he was. In their sleep John had slunk down farther on to the log, or Sherlock had pulled him, and had wound up with his chin resting in the fluff of Sherlock’s curls. Sherlock was clinging to John as though John was a large teddy bear, long limbs wrapped around John and holding him to him with his head pillowed against Johns bicep.

“Sherlock, gotta wake up,” John mumbled trying to pry Sherlock’s arm from around his chest. Sherlock snuffled and relaxed his grip allowing John to slip away and stand up, back popping slightly as he did so. _If we sleep at night again I’m leaving a note for Mycroft to leave blankets or we are sleeping on the rainforest floor, at least that’s soft,_ John thought, stretching.

Sherlock dug the beeping watch out of his pocket and turned it off, sitting up as well and stretching. He didn’t say anything just grumbled something and stood, trudging off towards their tank with John following close behind.

They stripped out of their clothes quietly as well, Sherlock giving a sigh before simply stepping off the ledge and into the water, dropping in like a stone. John sat and slipped in, the water actually jolting his brain and making him wake up quicker. Sherlock seemed to be far more awake as well, paddling away around the tank, looking out the windows. John noticed something off right away though, Sherlock had forgotten to take his scarf off before jumping in.

The pangs of transformation set in before John could swim over and tug the scarf off, and upon his eyes clearing up there was Sherlock, swimming along as a tuna, with a blue scarf looped over his head. If John could articulate a smile he would have been grinning ear to ear at the silliness of the sight. Sherlock didn’t seem to be bothered at all by the scarf so John left it alone, eventually it would fall off or Sherlock would change back with it and take the sodden thing off later.

Having slept through the night, John was more awake during the beginning of the day. He watched the people outside, ignoring the occasional reverberating bangs from particularly over enthusiastic children, circuiting between the window levels. That day they were visited by a couple of school groups, the groups of little yellow safety jackets making them easy to spot through the thick glass. John could vaguely hear joyful cries at the sharks drifting past; they didn’t seem to really care much about him or Sherlock other than pointing and saying how big they were.

About midway through the day John nearly had a heart attack, if fish could have heart attacks. Something big dropped into their tank, at first John could only see a large black object surrounded by massive curtains of bubbles. He darted for Sherlock who was drifting along up closer to the intruder, not entirely sure what he could do to protect the bigger tuna but wanting to be close to him and guard him nonetheless. 

The intruder turned out to be a diver, armed with a sponge and scrubber. Even though the threat identified as harmless John still stuck close to Sherlock’s side and kept an eye out for others. John watched as the person cleaned the inside of the windows and then, once finished, they reached down and gave one of the nurse sharks on the floor a pet. On their way up though, the diver changed direction, coming towards Sherlock. John lunged in between the two and the diver let loose some bubbles before reaching out to pet John, who promptly swam away, attempting to smack the diver’s hand with his tail and failing.

John felt a little bad for his maliciousness once he saw what the diver was doing. They removed the scarf which was still around Sherlock’s head, then left, scarf in hand, and John went back to Sherlock’s side.

“I _know_ they clean the tanks from time to time Sherlock, but you honestly can’t blame me for being a little twitchy after last night’s trouble!” John said as he toweled himself dry. He saw Sherlock’s smug smirk and wanted to toss the towel at him.

“You spent the rest of the day swimming next to me, one would think you were my shadow if you weren’t so brightly colored.” Sherlock chuckled, the deep laugh echoing nicely off the bare walls.

“Maybe I just liked staying close by?” Sherlock looked up from putting his pants on at that. Apparently John had struck a chord with that statement, Sherlock cocked his head a little and stared at John.

“Why?” He asked, confusing John for a moment. _Why what? why do I like being near you or why do I want to protect you from kidnapping assholes?_ John thought about how to reply to Sherlock’s question. 

“Because I actually like you,” John finally said and watched as Sherlock’s eyebrows rose. John didn’t understand what was so shocking about that. They’d been stuck together in the aquarium for weeks with only each other for company. Sure there was room to get away from Sherlock by going to another area of the building, but John found he never really wanted to, and now that there seemed to be someone out to get them he especially felt the need to stay near Sherlock.

“I’m the reason you’re trapped here.” As though that was a perfectly valid reason for hating Sherlock’s guts and not being concerned about his wellbeing. 

“You were just defending yourself,” John replied, the conversation definitely had to have been one of the stranger ones he’d ever had while naked let alone with another man and he became suddenly more aware that Sherlock was partially clothed. He reached for his own pair of pants and trousers to have some sort of cover while they continued their conversation. “I do like being around you.”

“I’ve not given you any reason to,” Sherlock said shrugging into his robe and cinching the belt tight, looking as though he were almost trying to hide in it.

“You’re smart, clever, fascinating, sure you can be a bit of a rude arse sometimes, but I enjoy your company and you seem to like mine, especially last night.” John smiled at the memory of Sherlock cuddling, glued to his side like a sleepy limpet. Sherlock’s face reddened and he started shuffling off towards the door.

“Well, er, stressful situations,” he lamely attempted as an excuse, while John slipped his shirt on and followed him with his own robe over his arm. John just huffed a quiet chuckle.

They were met at the gift shop by one of the McDonald’s employees holding a tray with a couple bags of food. She had a nervous smile on for them, her eyes darting to their necks first, seeing that their gills weren’t covered. 

“Our manager told us to bring you your food tonight, if, if you want something else, er, I can go get it for you, it’s just the regulars said you order just about the same thing every night.” She stopped talking, seeming to notice she was starting to ramble. John gave her a smile.

“It’s alright, I’m sure the whole mess last night was a bit of a scare for you lot,” John said, taking the bags from her tray, “We’re genuinely sorry that happened.”

John saw her eyes go to his neck again. “Not to be rude or anything, but, what happened to-” she carefully pointed at John’s gills.

“Not entirely sure, we’re trying to figure it out. Very hush hush stuff, best not to tell anyone else about it.” John told her in a secretive whisper. She nodded quickly motioning as though she was drawing a zipper across her mouth. John chuckled and thanked her for the meal and her small vow not to talk about the gilly men in the aquarium.

Sherlock and John sat and ate their meal together in a corner near the stingray pool, the floppy fins of the rays peeking over the edge of the tank now and then. Their night continued quietly. Sherlock appropriated a computer for some e-mail and website checking and a few easy cases to solve. After a while he gave up on that and slumped down onto John in front of the whale skeleton tank, they sat there talking for a while with Sherlock’s head resting in John’s lap. They both dozed off together again, John’s hand in Sherlock’s hair, only to be awakened by the alarm telling them to get back in the water.

The following two weeks continued like that, the pair coming together a little more every night. It was quiet and calm, Sherlock would get a little stroppy over a case now and then because ‘forensics can’t take photographs to save their lives, John’ or something similar. 

They would come out of their tank at nine ‘o clock every night, the transformation coming easier and easier for John with each night. Sherlock would help John out of the tank and wait for him to get dressed because he was still always the first one out. At some point along the line Sherlock began helping John dry off, and John helped dry Sherlock’s curly hair.

The tuna men would meet with the same lady with their fast food where she waited in the gift shop for them. She gradually got used to seeing them and their gills and after only a few days she was just as friendly and calm as she was before when she’d seen them from behind a counter.

Sherlock actually started following John around the tank when they were fish. John didn’t notice at first, so caught up in his usual swimming pattern that he didn’t see the larger tuna trolling along right behind him. The pair accompanied each other around the tank Sherlock nudging into John now and then. It was after a day or two of the companionable swimming that Sherlock seemed to suddenly become excited and darted out in front of John, cutting across him and making him come to nearly a halt. Sherlock floated into his line of sight and began flicking the webbed dorsal fin that was usually retracted flat to his top.

John watched the little fin go up and down as Sherlock started folding and unfolding it furiously near him, he was beginning to think his friend had finally lost his mind when he started to see a pattern to the flicks. A dash a pause a couple more dashes here and another pause there. 

_O - R - S - E - ? - M -O - R - S - E - ? - M -O - R - S - E - ? - M - O…_ John nearly shot forward in excitement, Sherlock was signaling with his fins, they had at least some form of communication available to them while stuck as fish!

 _Y - E - S,_ John signaled back trying to remember his code quick enough to reply. They both started racing, thrilled at their discovery. Forgetting themselves in their happiness, they sped around the tank, making a bit of a spectacle for the onlookers beyond the glass. 

Even with their extremely limited ability to express emotions John could only describe Sherlock as ecstatic. Once he’d finally slowed down and came back to John, Sherlock began rapidly flicking code at him drifting and then turning around almost like he was pacing next to John. John quickly lost track of what exactly Sherlock was trying to tell him though, and he jerked forward to nudge Sherlock in the side, interrupting his ‘pacing’.

 _S - L - O - W - E - R,_ John signed at him, putting extra pauses between each letter trying to convey the idea to the frenetic fish before him.

Sherlock tucked his fins in again against his body and kicked himself in an exasperated small circle. If he’d been able to huff or roll his eyes John was almost certain he’d be doing so. But Sherlock did eventually come back to him and slow down his signals to a point John could understand, it was a sluggish and mildly tedious form of communication, but at least it was something, and after nearly a month of fishy silence during the day they both were happy for something to occupy their time.

When John surfaced with a coughing gasp that night Sherlock was right there at the edge of the water, long fingers grabbing onto John’s head, curling under his jaw. He felt lips quickly pressed to his hairline, a few small smooches added to his forehead before Sherlock let him go and helped him clear his eyes and ears as usual.

John sat back in the water for a moment longer after that, mildly stunned by the sudden happy affection showered on his forehead. Sherlock was nearly done with his drying when he seemed to realize John was looking at him and he in turn looked back with a small curious tilt of his head.

“You, er,” John wagged a finger at his own forehead.

“You know morse code,” Sherlock replied as though that answered John’s implied question.

“You kissed me on the head,” John finished, starting to pull himself up out of the water onto the edge of the tank.

Sherlock was quiet for a moment, seeming to only just realize what he’d done and not sure what to say about it. “Bit not good?” he asked looking at John out of the corner of his eye like he wasn’t sure if John wanted to face him after the error.

“No, oh, no, just unexpected that’s all,” John said, chuckling a little to lighten the mood and show Sherlock that he honestly didn’t mind the contact, only that he’d just been caught off guard by the ambush kissing.

The rest of the night continued as usual. Sherlock rifling around on the computer for a while after dinner until he decided he’d had enough and slumped into John, falling asleep on him after a bit of mumbled conversation and an absent minded peck on the cheek as he drifted off. John couldn’t help a small smile growing off and on through the night at the innocent kiss from Sherlock. 

Mycroft was the one who became the killjoy for the tuna pair. A few days after the discovery of their morse code capabilities Mycroft appeared at the window of their tank. Dressed formally as usual, umbrella and all, he sat down facing the glass and proceeded to unfold the paper under his arm. 

After floating by a few times trying to read the news, Sherlock darted to John, fin flicking a short message, _S - T - O - P / C - O - D - E._

The urgent message made John want to see what Sherlock had read on the paper and managed to catch Mycroft before he folded it away. There on the offered page was a small article questioning “Are Sea Life’s Fish Intelligent?” Below was a little black and white picture of their tank and, sure enough, the black shapes of John and Sherlock within. The paper itself was one of those silly “Are aliens cavorting amongst my sheep?!” types, but still, the fact that someone had written in to say they’d seen the fish at the aquarium doing code and talking to each other in an intelligent manner was unsettling. And who knew who else would see it and start watching a little closer.

That night Sherlock threw a small fit over Mycroft being an overbearing fusspot who can’t let him have something nice in this hellhole. John stopped himself from laughing at his tantrum, because a man of Sherlock’s height and lankiness looked rather silly stomping about in the nude. He instead managed to coax Sherlock into his night wear of soft pyjamas and dressing gown, the man still grumbling at him even as John pulled the towel out of his wildly gesturing hands and dried him off first. 

It wasn’t that John wasn’t upset about his means of communication during the daytime going back to nil, just that he didn’t see much of a point getting as physically huffy about it as Sherlock. He kept his anger inside for now and focused on getting Sherlock to settle for the night. If John had the chance he honestly felt he would love to slap the elder Holmes with his tailfin. Seeing as that was unlikely to happen though, John simply sighed and dragged Sherlock away from their tank and settled in elsewhere in the aquarium to eat their nightly ration of fast food.

Sherlock eventually settled grumpily against John’s shoulder. John patted him comfortingly on the back with a small, “there there,” and he slumped down even further to lay his head in John’s lap. John knew now that Sherlock enjoyed his hair being played with and a hand buried itself into the dark curls right away. Sherlock was out like a light within the next half hour and John followed him soon after.

Sherlock continued to sulk for the rest of the week. He’d still settle in next to John when he got tired and he’d stay near John when they were fish, but Sherlock would be grumpy about it and act like he didn’t want to and make excuses for why he decided to use John as a pillow. John watched Sherlock shuffle through his case e-mails and become flustered by his inability to go to the ones that looked genuinely interesting. His heart went out for Sherlock, he knew after weeks living with him how easily bored Sherlock got, the new discovery of being able to occupy his mind with the coding had been wonderful. John still fondly remembered the kisses Sherlock had showered on him.

John decided to do something for Sherlock, something to break the monotonous routine of their lives at the aquarium. But what? It wasn’t like they could run out and just go do anything. Sherlock loathed the gaming arcade upstairs and they didn’t have the cash for that anyway. Anything else would require them to go outside. They were right in the heart of a major hub of London attractions, the London Eye sitting right outside their front door and just north up the Thames a park and food and theater and just across the bridge a tube station and Big Ben. But none of that mattered because they couldn’t leave their aquarium. Mycroft hadn’t returned with any new news about the origins of the shark twins, therefore they had to treat the outside world as though a new enemy would jump them the moment they got near the exit.

The idea came to him as he looked over Sherlock’s shoulder at the computer, a flashing advert on the side of the page. John could order in dinner for them, something actually good rather than their usual crummy fast food. That night he dug out the card they’d been using to pay for their food before the shark incident and found another computer away from Sherlock.

He tried to work quickly so Sherlock wouldn’t find out, John had no idea when his case e-mails would run out for the night or if he’d notice John going missing from his spot behind him. He pecked at keys and tried to search for something good, something they would both enjoy having as a special dinner. And then he remembered Sherlock telling him about a restaurant near his home and a case that saved the owner, Angelo’s. John typed it in and sure enough they worked with the delivery service, a wide grin spread across his face at that just knowing that they were going to get better food for once, and good Italian food too. For once John would be able to surprise Sherlock.

John made the order picking things he thought they would both like, nothing with fish, thank you very much. When it asked for when he wanted the food, he put in for the order to come the next night and included instructions for how to get to them in the message box. With a triumphant click and a smile John placed the the order.


	5. Romancing the Fish

**Notes for the Chapter:**

> Thanks Nautilicious for being my beta. :)

Of course Sherlock knew something was up the moment John reappeared. John tried to act cool and brushed the suspicion off with an admission to the fact that he hadn’t checked his own e-mail in nearly a week. Sherlock eyed him for a moment before giving up and going back to his screen.

It was another couple of hours before Sherlock finally shut down the computer and pulled John away to the comfortable spot they’d found to sleep in, a bench alcove near their tank that had mysteriously been covered in a thin padding one day. John was certain he had Mycroft to thank for that. Sherlock let John sit down and get comfortable before he took is place next to him. They had an unspoken agreement that John would fall asleep sitting up against the wall with Sherlock’s head in his lap and John’s fingers twiddling with his hair; then sometime in the night John would shuffle down and Sherlock would become a limpet on his side.

When they became fish in the morning John stayed right by Sherlock, brushing him with his side and fins now and then, just keeping the poor bored tuna man close company throughout the day.

Sherlock definitely knew something was going on the next night when John shot out of the water so fast he nearly passed Sherlock coming out. John helped towel Sherlock off and ruffled his hair with the towel. Sherlock grabbed John with a towel before John could set about cleaning himself.

“What has you in such a good mood?” Sherlock asked, as he covered John’s head and ruffled him as well. 

“A nice surprise, you’ll see in a bit,” John replied, batting away the playful towel. They dressed and John led Sherlock up to their normal meeting place to retrieve their food. Sherlock seemed very wary of whatever the ‘surprise’ was and trailed behind John, who could almost feel his eyes boring into the back of his skull.

John stepped forward to claim the bags of food from their friendly McDonald’s employee, Emma. She wore a mildly confused expression. “These came for you a few minutes ago, said they were for a Mr. Holmes. That’s you, right?” Emma looked to Sherlock, who hung back near the doorway.

“I placed the order, Holmes was the name on the card, thank you so much for bringing it for us,” John said with a large grin. He could smell the lovely scent of garlicky Italian emanating from the bags. 

Sherlock’s eyebrows went up when he saw John return to him with the very different looking bags. “You bought dinner?” he commented, eyes going to the bags before shooting up to John’s grinning face.

“Excellent deduction, but I not only bought dinner, I bought us a nice tasty filling Italian dinner sure to be full of flavor that I for one have been missing for ages, oh eater of squid bits and pellets,” John said gleefully. He handed Sherlock one of the bags to carry and drew him back into the depths of the aquarium, with a hand on the small of his back, to enjoy their meal.

They settled in near the multicolor glow of the moon jellyfish tank, the delicate jellies slowly floating around their circular enclosure. 

“You ordered from Angelo’s.” Sherlock seemed to be in a small comments sort of mood, seeing as the only things he’d said since they got out of their tank that night had been barely more than four words and then curious silence.

“How can you tell?” John said, looking at the generic paper bags, devoid of logos.

“You ordered the food, I assume you were not thinking only of yourself when you made the order, so you tried to find something that would appeal to the both of us. The only clue I have ever given as to my cuisine preferences was when I relayed the story of Angelo’s housebreaking alibi, so Angelo’s Italian restaurant. Also, judging by the weight distribution in this bag, and the sound, there is a fairly substantial bottle of what I believe is Italian Grappa, which Angelo has been attempting to gift to me since I cleared him of the murder charges,” Sherlock said, sitting down with the bag in front of him and looking into it. Sure enough, he pulled out a tall slender bottle of clear liquid, with a tiny gold label circling the base reading ‘Grappa’.

 _Ah, there are his words,_ John thought, eyebrows rising a bit at the bottle of liquor he certainly hadn’t ordered. 

“That’s incredible, brilliant,” John said, as Sherlock peeled a little yellow sticky note from the back of the bottle.

“Light candles, it’s more romantic.” Sherlock said, apropos of nothing. 

“What? Romantic?”

“Angelo,” Sherlock held the note up for John to see the scrawled message on it. “He seems to think that I have come to him to cater for a date.” 

“I swear I didn’t ask for that-” John began.

“Of course not, he saw my name on the card, noticed that it was an order for two and as he is wont to do, assumed I had a date.” He set the bottle down and continued to rummage through the bag, pulling out containers of food and setting them aside. With a tiny ‘ah’ Sherlock pulled out something from the bottom of the bag, a little book of matches and a white votive candle. 

“Is this a thing that happens often? Him trying to set you up on dates?” John asked with a pointed look at the bottle of grappa and candle.

“Not as such, no. Though he has stated that he thinks I am ‘lonely’ and ‘need someone to feed me up a little’, oddly loyal but fairly harmless man though, Angelo,” Sherlock replied, popping open the book of matches and lighting the votive. He began popping open the food that shared the bag with the grappa, and placed the votive in the plastic top half of his salad bowl to catch wax. He set the candle down between them near the wall, the jellyfish above catching a little of the warm orange light.

John arched his eyebrow at that. “You’re actually going to use that?” he asked following Sherlock’s lead and pulling the various components of their meal out of his bag too. 

“I see no reason not to, it adds a nice little bit of extra light to an Italian dinner,” Sherlock replied digging their plastic utensil sets out of their bag and handing one over to John. 

John had forgotten to order drinks, but the lovely Emma had seen the bottle in their bag without glasses and had put a pair of small McDonalds cups in the other bag. John looked from the empty M emblazoned cup to the unopened bottle sitting next to Sherlock. Grappa wasn’t exactly like wine, it wasn’t meant to be served up in doses more than a shot glass. But it was something to drink, and it was either that or water.

“Do you drink?” John asked, picking up the bottle.

“A bit in Uni, rarely since other than the occasional experiment,” Sherlock replied, not looking up from his salad. 

“Well, just a warning, sip this stuff,” John said, taking the wrapping off the top before looking dumbly at the cork. “We don’t have a corkscrew.”

Sherlock sighed and set his fork down, plucking the bottle out of John’s hand. “Give me your shoe,” he demanded, holding out a hand for said item. John pulled off one of the loafers that had become that week’s pair of shoes and handed it to Sherlock, who stuck the bottle into the heel of said shoe. He turned it sideways and soundly thumped the heel and bottle against the wall a couple times, sure enough the cork popped loose. Sherlock handed the bottle back to a slightly smiling John.

“Well that’s a clever party trick,” John chuckled, pulling the cork the rest of the way out and pouring a little into each of their cups. 

“Simple science,” Sherlock replied casually, returning to his salad. John pretended he didn’t see the small smile that sheepishly curled the corners of his mouth, and unpacked his own small salad. 

They ate the first part of their meal quietly, enjoying the change of textures and tastes for the first time in over a month in John’s case, even longer for Sherlock. Then Sherlock reached for his drink and drained it in one gulp. John couldn’t help but snicker as Sherlock coughed. 

“Told you to sip it,” he said between chuckles, taking Sherlock’s cup and pouring a little more for him. Sherlock acted like the coughing had never happened, with an air of “meant to do that” as he took the cup back and took a tiny sip of it.

They then served the main course of their dinner, taking the larger containers out of the bag, happily still warm. The warm yellow flicker from the candle between them provided a nice glow that lit the angles of Sherlock’s face nicely. The candle sat between them alongside the bottle and their food set out with them facing each other, a bag of warm bread open to share in the middle. Combined with the ever-changing glow of the nearby jellyfish tanks and their delicate occupants to either side of them, blue to purple at that moment, it actually did look fairly romantic. 

“I wasn’t entirely sure what you would want so I didn’t pick anything too outlandish. I ordered you spaghetti bolognese. No fish, or scallops or calamari or anything that came out of the water. I can trade if you think you’d want something else,” John told him suddenly realizing the rather date-like nature their nice dinner had taken and stumbling over his thoughts. On one hand he hadn’t intentionally created a romantic candlelit dinner date but on the other hand he had wanted to make Sherlock happy, even though it was just food it was something nice and different.

“This will be fine,” Sherlock said, stopping John from babbling any further. John watched as Sherlock stirred his pasta a bit, twirled his fork, then took a first bite. Sherlock sat cross-legged with the takeaway container held in his lap. He brought the box up half way as he took the bite and quietly slurped the pasta between his lips, his tongue darting out to lick the corners of his mouth. “Thank you.” John saw Sherlock’s mouth form the words, so sucked in by watching him eat for a moment that he’d forgotten about his own food.

John picked up his own box containing meaty ravioli and began eating as well, and the dinner continued on. Their fingers brushed in a moment when they both reached for the bread at the same time. At one point Sherlock sucked his spaghetti in and accidentally managed to flip a noodle up onto his nose. Before he even really thought the action through John had reached out with a paper napkin and wiped the sauce off Sherlock’s nose for him. Sherlock’s eyes crossed where John’s finger stopped mid-wipe at the bridge of his nose and John quickly retracted the napkin with a small embarrassed cough.

“Sorry, don’t know why I did that,” he apologized, Sherlock didn’t reply just continuing on with his meal. 

John refilled their cups as they ate, Sherlock sipping his down easily after that first surprise belt. They drank in turns even after the main dish was done, Sherlock’s container completely empty, much to John’s surprise. Sherlock almost always had small bits of things left over; it made John happy to know that Sherlock both enjoyed the food and ate a proper full meal.

A warm, fuzzy, sleepy sort of feeling slowly crept in on John and he realized the grappa was beginning to get to him, and then he realized Sherlock was kneeling next to him pulling at his arm, _when did he get there?_ John wondered slowly, looking over at Sherlock who was telling him something.

“Let’s walk John, we-we never walk much. Our feet. We have feet, we can use our feet and go for a walk.” It was at that moment John realized that the bottle of grappa, basically empty save for a miniscule portion in the bottom, was in Sherlock’s other hand, the bottle dragging on the floor as Sherlock shook John’s arm, “John, we should walk together.” Sherlock asserted again, with the same babbling, slurring, voice.

“Sure, yeah, we can do that. Just let me clean up first,” John replied, feeling a little wobbly but not nearly as much as Sherlock seemed to be. The moment Sherlock let go of his arm Sherlock just sat there on his knees swaying side to side a little bit like he was being pushed and pulled by invisible gentle waves. John figured out just how much the grappa was affecting him as he fumbled with their empty containers, trying to crunch them back into the bags they’d come in.

John was reaching for the still lit votive candle when Sherlock, with a surprisingly quick motion for one so drunk, snatched it away, mumbling, “I have it, I’ll put it out.” Then he proceeded to try to blow out a candle, which the drunken part of John’s brain found absolutely hilarious as the genius detective failed multiple times to get the little flame to go away. He finally got it to go out with a huff at John’s laughter, bringing them back to only being lit by the glow of the large jellyfish tank behind him.

Sherlock tipped his head back to look at them upside down, the delicately floating creatures slowly rotating around the drum of their container. “Well those are nice,” Sherlock said, as though the jellies had hypnotized him in the brief time he’d stared at them. 

“Come, come on Sherlock you wanted a walk right?” John said, gradually getting to his feet and standing above him. Sherlock’s head slowly tilted forward again.

“Oh, yes, walk let’s take a walk,” Sherlock’s face broke into a ridiculous wide grin and John watched as he began the struggle to stand up, nearly making it before landing back on the floor on his arse. “My legs seem to be malfunctioning, John,” came the detective’s plaintive moan.

“Here,” John reached down and took one of Sherlock’s arms, one hand on his elbow the other gripping his large spindly hand, and together they managed to get Sherlock standing. It was absurd, the pair of them, grown men, one of them far more drunk than the other, propping themselves up in the hall next to the row of jellyfish. Sherlock was like a newborn colt on his feet, leaning heavily into John at first before swaying in another direction and detaching himself to take a handful of steps and plaster himself to the glass of another tank with a few long cream and orange colored jellies.

“Well these are quite nice too,” he mumbled at the pretty creatures.

John wandered over to him chuckling and wrapped an arm around Sherlock’s waist, pulling him back into his side. The pair of them wobbled on through the aquarium, John laughing his arse off at Sherlock’s sporadic comments about the creatures in the various tanks big and small along their way. 

When they came to their home tank with is massive head statues and sharks Sherlock stopped and stared at it, just sort of staring into nothing for a moment and John’s giggling died out.

“What’s the matter Sherlock?” He asked.

“We live in that,” Sherlock replied staring into the tank, he moved away from John again wobbling over till he was pressed forehead and nose squashed against the thick wall of acrylic.

“Yeah,” John replied a little dumbly.

“I met you and we live with a bunch of sharks and-and silver trevally fish,” Sherlock stated bluntly. John could see his light blue eyes wide and staring into the tank that they spent a major chunk of their time swimming in. He could almost feel Sherlock spiraling into becoming a gloomy drunk as Sherlock continued to stare, forehead against the glass as though he was about to sink through into the blue water beyond. _Well that just killed the fun,_ John thought ambling over to Sherlock.

“Come on let’s keep going,” John said tugging Sherlock away from the window. Sherlock hobbling along easily until they were out of sight of the shark tank.

Just around the corner was a bright bubble of a tank filled with small clownfish all fluttering around in their own little enclosure protruding slightly from the wall. Sherlock looked down at it as they passed. “At least we aren’t stuck in there,” he said quietly. There was a beat of silence as they both started down at the bubble of tiny orange and white fish, and then Sherlock snorted a laugh. Which started John giggling again, and they continued on their walk.

They entered the stingray room, a wide open pool where, during the day, children could get up close and sometimes touch the medium sized, flat, shark relatives. Sherlock chuckled and laid himself out over the large faux rock that made up the back wall of the tank, where a short waterfall stirred the waters. “John, look at these.” Sherlock said, shimmying a little further onto the rock on his belly, to the point that John swayed after him and grabbed a hold of Sherlock’s waist to keep the enchanted drunk from falling headfirst into a tank load of stingrays.

John looked over at the sign right next to them reading ‘Please do not climb on the rocks’ and with his cheek smushed into the bared small of Sherlock’s back he said, “Sherlock, what’s the sign over there say?” as though he was reminding a child of the warning he’d blatantly just ignored.

Sherlock squirmed his way back up till he could look back at the sign as well, sending the both of them tumbling slowly backwards onto the floor, Sherlock sitting on John’s lap. Sherlock squinted at the sign hard before replying. “Don’t.” Sherlock said with a snorted snicker.

“John, there’s no rocks in here,” Sherlock giggled, still sitting on a rather pinned John, who had his head laying back against the glass of the mullet fish tank that created the other side of the walkway.

“Then what do you call that thing you were climbing on?” John asked with a huff.

Sherlock launched himself up to his feet and stumbled a step or two before turning to face John and smacking his hand down onto the rock for stability's sake. “Painted… fiberglass,” he crowed, patting the fake stone a few more times before stopping and looking down at his hand, “or maybe concrete,” he mumbled looking at the reddening palm of his hand from where he’d just slammed it down against the very solid surface with a little too much force.

John got up and followed Sherlock’s wobbly path as he wandered around towards the front of the stingray tank. Sherlock’s fingers dipped into the water as he gripped onto the edge of the tank. John was thankful that he was slightly more sober than Sherlock in that moment as Sherlock suddenly jerked his hand away from the water in a wild flail, giggling at the ray’s fin that had brushed up against his fingers and come out of the water to flap over the edge a bit.

John caught him and pulled him over to sit with a light thump on the nearby bench before Sherlock could hurt himself, it was a wonder that they hadn’t managed to bump and bruise their way through their drunken walk all the way from the jellyfish to the stingrays. Sherlock was still emitting a light, higher-pitched giggle as he slumped back against the wall, taking John with him. 

“Look, John, look at the flaps,” Sherlock laughed pointing at the small horde of stingrays that had congregated at their side of the tank, fins flopping out of the water and slapping up against the glass in the air before slipping back below and skating along the sandy bottom. John did chuckle at the sight of the enthusiastic flat sharks. 

Sherlock continued to drunkenly babble at the rays. “Flat flops, flippery flop flops, flapping,” he chuckled, a deep throaty noise compared to the high pitched giggles before, “flap flaps John.”

“What?” John said, following Sherlock’s swaying pointing finger to squint at the stingrays.

“Sea flaps, they’re sea flap flaps, flippery flappy fish,” Sherlock laughed, putting his long fingered hands together, crossed at the palms, to make a sort of bird wings flapping motion with them.

John laughed along with him. “Sea flap flaps, that's ridiculous,” he said, snorting as he looked over at the rays and sure enough there they were flapping along in the water, fins breaking the surface now and then to wave in the air.

The pair eventually ran out of steam there, staring at the broad tank. Sherlock leaned heavily into John and John leaned back, propping each other up, Sherlock’s head on top of John’s with his cheek pressed inelegantly into John’s hair as he blinked lazily. John had actually thought Sherlock had fallen asleep on top of him and nearly startled when the deep baritone spoke like a voice from God above him through his skull.

“Your hair is soft John,” Sherlock stated, head rocking gently to rub his face against said hair like a tall cat.

“Hmm?” John hummed in reply.

“Matches that stripe on your side, when we change,” Sherlock mumbled, “looks nice.”

“Huh?” Sherlock sat up, abruptly taking away John’s leaning support and causing his head to flump down into Sherlock’s lap. Sherlock looked lazily down at him, eyelids at half mast, small goofy smile on his face, the picture of a contented, and rapidly approaching sleepy, drunk.

“Like you,” Sherlock murmured, smile growing, fingers trying to pick at John’s hair and insinuate themselves against his scalp.

“Well I like you too you know that,” John replied struggling to sit up again and barely managing to remain upright once he got there, body nearly continuing in the path it was on and toppling over. He looked at Sherlock who in turn looked back, the pair of them facing each other on the bench. 

Sherlock’s hands came sneakily up the sides of John’s face, burrowing up into his hair again, “No, Like you like you,” Sherlock said, as though John had completely missed his meaning.

And suddenly there were lips involved, Sherlock’s hands were holding, cradling, the back of John’s head, tilting it up so that Sherlock could come down and plant his lips against John’s. John’s eyes popped wide as though Sherlock’s lovely soft lips had just blown away the grappa haze momentarily. _Well this is gooooooood_ , John’s mind drawled before the warm blanketing haze came back and he leaned into Sherlock. It was sloppy but warm and soft, and Sherlock seemed to be really putting everything he had into the kiss, lips barely separating from John’s only to relocate and suck at his lower lip, kissing that lip then shifting up and giving John’s upper lip the same treatment, holding John’s head in place the entire time. 

When Sherlock finally pulled away, his hands still holding John’s head, the deep baritone said huskily, “like you,” then there was a light peck to the end of his nose and Sherlock’s hands let go, only for his arms to relocate under John’s in a bit of a bear hug.

“Sherlock?” Sherlock was repositioning them putting one leg up on the bench behind John and leaving the other to dangle off. He was pulling John with him as he laid back on the bench.

“Shhhhhh,” Sherlock shushed, quietly smiling as he pulled John to lay on top of him. Sherlock had John held like a teddy bear to his chest, long legs spread to either side of John on the bench.

“Sherlock?” John whispered at him trying to sit up, but pinned in the taller man’s arms. A small snore greeted him. In the moment’s after Sherlock’s head hit the bench, he had passed out asleep with a silly grin on his face and John in his arms on what certainly was not the most comfortable bench. “Well, great.”

John sighed and tried a couple more times to get up before giving in and repositioning himself to try and get a little more comfortable. He looked at Sherlock’s sleeping face and smiled a little before leaning up and giving Sherlock a small peck on the cheek and settling in for the night.


	6. Love You Like a Fish Loves Water

**Summary for the Chapter:**

> This is the chapter that earns this fic its E rating. That is your warning.

**Notes for the Chapter:**

> Thank you so much to both Nautilicious and DulcimerGecko for betaing this chapter for me.

Waking was a pain in the arse. John wanted to destroy the small beeping thing that woke him, but his arms just didn’t want to move. Sherlock snorted awake next to him. In their sleep, he had wound around John as he usually did, the limpet; and in doing so he’d ended up with the arm bearing the shrill little fuck of a watch right next to John’s head.

John finally sat up, divesting himself of Sherlock’s octopus grip, the room tipping and wobbling as he did so, and grabbed for Sherlock’s arm. The wretched little thing had to die. He ripped it off and pressed all the buttons until it shut up, at which point he threw the silenced bastard into the stingray pool where it floated down to the bottom and was promptly covered by a stingray and some sand.

Sherlock sat up next to him very slowly, holding his head as if he were afraid it was about to fall off his shoulders. He blinked at John sleepily, very slightly shook his head and blinked some more, groaning at the motion. He finally looked over to where the watch had been thrown. “That was my watch,” he slurred quietly, as though the sound of his own deep baritone were too loud for his own ears.

Hell, it was almost too loud for John’s ears as he winced at the splash of the watch and Sherlock’s mentioning of said offensive item. “It needed to die,” John whispered vehemently.

Sherlock suddenly lurched up, staggering upright with his knees together for balance. “That means we’re fish, about to be fish!” Sherlock said it far too loudly, causing him to veer to the side at the power of his own voice. John shot forward to catch him before he hit his head on the concrete wall.

“For the love of god, stop,” he grumbled, “you’re gonna crack your head open if you keep that up.” John threw one of Sherlock’s arms around his shoulders before Sherlock could wobble off.

“Gotta get to the water, John,” Sherlock mumbled, plopping his head down on top of John’s with a small groan. “Why’s the room spinning?” 

“Cause you can’t hold your liquor for shit apparently,” John replied, tugging Sherlock in the right direction as they propped each other up. At Sherlock’s questioning grunt he added, “Hangover Sherlock, hangover.”

“Ah,” was the only sound John got in reply as Sherlock snuffled into his hair.

They continued their wobbly way back towards their tank, John incredibly thankful that they had passed out close by, until they went through the door and he saw the stairs they had to climb to get to the top of the aquarium. It was slow going up the stairs, and John kept a very tight hold on Sherlock just in case. At the first rough squeeze from John’s arm around his waist keeping him from tripping headlong over the handrail Sherlock let out a low coo and John felt lips in his hair kissing at the top of his head.

Thankfully they reached the top without incident but now came the task of getting undressed and into the water. Sherlock seemed a little more stable on his feet when John let him go but he just stood there as John began stripping. John looked up to see him watching, with half-lidded pale eyes and a small slightly goofy smile.

“Now come on, you know the drill better than me, clothes off,” John said, grabbing onto the bottom of Sherlock’s shirt and pulling it up over his head. He heard a deep chuckle come from under the fabric and once his head was freed Sherlock leaned forward and planted a kiss right on John’s nose.

 _Ah, so it wasn’t a one time thing,_ John thought as Sherlock pushed a gentle kiss to John’s temple, another on his cheek, and another right in front of his ear. John pulled away with a small chuckle of his own. “Alright, Mr Affectionate, much as I like whatever this is you’re doing, we gotta get undressed,” John told him, hooking thumbs into Sherlock’s shorts.

Sherlock let out a sigh and let John pull down his remaining clothing. John taking note that at least Sherlock wasn’t sporting anything embarrassing as he knelt down before him to help him lift his feet one at a time. He however was a little less unaffected by the kissing, not hard per say but if Sherlock kept going John would have something to be red-faced over.

Straightening up, John looked into Sherlock’s slightly hooded eyes, smile still plastered on his face as he gazed blearily into John’s eyes. Taking pity, John leaned forward and laid a rather chaste kiss on Sherlock’s lips; he didn’t fail to notice Sherlock’s head following his as he leaned back.

“Don’t think we’re not going to talk about this later,” John said, nothing but affection in his voice.

“Mmmhmm,” Sherlock hummed, leaning into John and wrapping his arms around him in a hug. John didn’t have time to catch the smirk that spread across Sherlock’s face before the man used his taller body to sway them towards the water next to them. He suddenly fell sideways and John, caught in his arms, went with him. The madman laughed at John’s startled face when they splashed into the water. 

They floated down and Sherlock still clung to John, grinning his face off and very clearly still laughing even though there was no sound accompanying it. John reached up and pushed at Sherlock’s head playfully, trying to get him to let go. The grip broke easily and they separated, floating away from each other like astronauts in space. 

John managed to swim alright, even with the mild effects of a hangover still clinging to his head, but as John looked back at Sherlock he realized Sherlock was still very much feeling his hangover because he just kind of gently turned in place in the water. John watched him as he paddled away, trying to right himself with none of the grace Sherlock usually held in the water. He watched long, slightly webby toes and fingers spread and kick and Sherlock propelled himself into the glass nearby. With a chuckle, John saw him shake his head and palm the glass a little before he turned and tried to paddle in another direction only to drunkenly bump into something else.

And then the change happened, and John’s amusement only grew as Sherlock listed around the tank, still bumping into things but at least his more streamlined fish body let him slide by. Then he’d pick up a burst of speed, riling up the other fish around him before slowing down, leaving a confused school of fish swarming around him for a moment until he did it again. 

John took pity on him eventually, moving over to Sherlock’s side and keeping him oriented properly. The loud noises of children banging on the windows, which had at one point scared John, now seemed to startle Sherlock; he would dart when they happened, only to slow when he figured out what it was.

Sherlock finally returned to his normal self after some time, but even after, he stuck close to John rubbing into him now and then in what John interpreted as affection. And John was just fine with that as they continued to swim slowly around their enclosure.

Surfacing that night, John was met with a pair of lips on his forehead before he could even wipe the gel from his eyes and ears. Sherlock, as always, beat him out of the water and when John finally emerged he was ready for him with the towels regularly left for them.

He grabbed John’s head and cleaned his face meticulously before planting a soft kiss on John’s dried lips, holding there for a very long moment before he finally pulled away with a sigh.

“Aaaah, much better without the alcohol,” he mumbled, rubbing his nose along John’s and brushing his still sopping hair against John’s forehead.

John chuckled. “You’re sober now, mind explaining the kissing?” John asked, grabbing a nearby towel and beginning to scrub Sherlock down as well.

“Do they usually need explanation?” Sherlock replied from under the towel as John ruffled his hair dry. 

“When they come out of nowhere as a surprise snog in the night, I would think so,” John said good-humoredly. He wouldn’t lie and say he didn’t enjoy it, he just wanted to hear from Sherlock what this was, this new thing between them.

“I,” Sherlock began, then paused when John rubbed over his chin and up his ears. “I find that I am rather… fond of you, John,” he said a smidge awkwardly.

“Fond?” John thought that that was rather sweet really. He liked Sherlock just fine, of course. Having spent the last month or so in close quarters with the man, as both a mysterious fish and a human, had given them plenty of time to get to know each other. Having a percentage of that time be spent naked both in and out of the water didn’t harm things either. Sherlock was quite handsome if one were to ask John, which only made him wonder what Sherlock saw in him. A quick glance down at himself revealed a very slight pudge, formed while invalided home and in hospital, covering what had used to be quite a lot of muscle. The mangled scar on his left shoulder didn’t make things much better, let alone the small nicks and scrapes from other incidents. John knew what he saw in Sherlock, but what on earth did Sherlock see in him?

“I’ll admit I didn’t particularly plan last night; I had hoped that maybe after this whole mess with the fish I might be able to… woo you back to my flat, if you weren’t absolutely driven away by me once you reclaimed your freedom. The alcohol rather loosened my tongue, as it were,” Sherlock explained, taking hold of one of John’s legs and continuing to clean him off.

“Woo?” John replied with raised eyebrows and a small laugh. Well that wasn’t exactly the answer he was expecting.

“I actually do find you attractive as well, so you can stop all the looks and the crises,” Sherlock added, finishing with the leg at hand.

“You find me attractive!” John yelped, right at the moment Sherlock decided to playfully draw a long finger up the bottom of his foot, making him impulsively yank it away at the tickle. 

“Of course I do. You’ve got a soldier's build, lovely, stocky, muscular. Your scars are not ugly, they are part of you, your past, your story. If it weren’t for the obvious infection you sustained after the bullet, I could probably tell you the caliber of the round that brought you down. But you are handsome, from the top of your blond head to the bottom of your soles.” John jerked his other foot away from Sherlock before he could tickle that one as well.

“Don’t you dare,” John snapped at him, taking the towel from him and finally wrapping it around his waist. Much as he wanted to continued drying Sherlock off, he wanted something between his arse and the cold slimy concrete. 

“Doesn’t hurt that you’re rather impressive to look at below the belt, shall we say, and I haven’t even caught you hard, yet.” Sherlock added with a wicked smirk.

John looked away at that, face heating a little. He wasn’t particularly mortified by the comment, just mildly shocked by the bluntness of it.

“Oh, don’t pretend you haven’t looked at me in the same way. I’ve seen you staring; you seem to like my arse, my hands, my feet, and my hair, not in any particular order. But I have caught you staring at my cock on a number of occasions particularly while swimming--”

“I like all of you, you git,” John cut him off before he could go into further observations. “Yes, I do find you handsome too, and yes I’ve looked, kind of hard not to when you spend a portion of your time in the buff every morning and night,” John added, softening the admission a bit more after calling him a git. 

“So we are agreed, mutual attraction,” Sherlock said, before leaning in and properly kissing John on the mouth again, only to be interrupted by John’s stomach growling. John pulled away.

“Ugh, come on, we need to get dressed, Emma’s probably waiting on us,” John groaned as he got up. 

“You wouldn’t be nearly as hungry every night if you’d just eat the pellets and squid they give us every day,” Sherlock huffed, not even bothering with wrapping a towel around his hips as he followed John to the shelf that usually held their clothes.

“No,” John replied face scrunching at the thought of eating the raw squid bits. “I’m positively ecstatic that your breath doesn’t smell like either of those things when you’re human,” John added as he threw on his shirt. He did not fail to catch the displeased look on Sherlock’s face as he covered himself up with the nightly clothes. If Sherlock had his way, John would bet that he’d forgo clothes alltogether. He could imagine the conversation in his head and even there the excuse of ‘there’s no one else around’ didn’t fly.

As if in apology for disrupting their snogging with his stomach John leaned over and kissed Sherlock again once he was clothed, wrapping a hand around the back of his skull to hold him close, weaving fingers into the short hair at the nape of Sherlock’s neck. John continued to let his hands wander through Sherlock’s hair even after they parted for air.

“Mmm, one perk of this insanity we’re caught in, your hair hasn’t grown much if at all since we met.” John murmured, still carding his fingers through Sherlock’s curls. The man had a point, he really did rather like Sherlock’s hair and running his fingers through it.

“Neither has yours, call it a perk of being a fish for a large chunk of the day. I doubt Mycroft would be willing to acquire the services of a barber to come here so late at night.” John couldn’t stifle the laugh that bubbled up at the mental image of Sherlock emerging from the waters of their tank with long flowing locks of dark hair past his shoulders like a wayward mermaid. 

“Come on,” John finally said, taking Sherlock by the hand and leading him towards the stairs and their dinner.

Emma was indeed waiting for them, and John apologized for their lateness. She just gave them a slightly knowing look and told them it was no problem, leaving them to their meal.

They didn’t kiss again until later, sitting together on the padded bench alcove where they’d been sleeping: Sherlock pecked John on the cheek. The pecking drifted down to his jaw then to John’s neck, and that was a very different feeling as Sherlock kissed over the gill slits there. He looked up when John shifted and made a small humming noise, not sure if he liked it.

“Something wrong?” Sherlock asked quietly.

“Feels weird,” John replied honestly. It wasn’t bad, just odd. Sherlock backed away a little, still close but not breathing over John’s neck like before.

“Hmm, how about this?” he asked, bringing his hands into play. He gently ran his fingers along the edges of John’s gill covers, teasing the edges, rubbing them delicately, smoothing his hands down John’s neck before doing it all again.

That felt particularly good, actually, once John got past the strangeness of it. The edges were so sensitive sending little zings of pleasure down John’s spine as they were stroked. For the most part he didn’t even give the gills on his neck a thought when out of the water and often forgot they were even there until he caught a look at himself in a mirror or they were brushed by something like the collar of his shirt. John sank into the touching, letting off a light, pleasurable moan as Sherlock continued to manipulate the protrusions and incorporate them into a rather nice neck massage.

“Come here, you,” John murmured, reaching out for Sherlock before he got too relaxed by the massage. He wrangled Sherlock in front of him and got him to straddle his lap, all the while smiling lazily like a fool up at him. John sat back against the wall and pulled so that they were chest to chest, working his hands up Sherlock’s waist, over smooth pectorals, over prominent collarbones, and up to the same spot Sherlock had been teasing on him. 

Sherlock took to the stimulation quicker than John had as John gently ran both thumbs over the edges of Sherlock’s gill covers in a rhythmic motion. Sherlock’s hands went back to John’s neck and together they took advantage of this new way to pleasure.

“See, weird,” John said watching Sherlock’s eyes close with a slightly blissful look on his face as he bent his neck into John’s hands like a massive cat.

“Oh, but good,” Sherlock rumbled, and John got to feel that deep pleasure-roughened baritone from the bottom of Sherlock’s chest and in his fingers on his neck. John pulled lightly and brought his lips to the adam’s apple bobbing between his thumbs. He smiled into the skin as Sherlock hummed happily. John nibbled his way up the path Sherlock had taken earlier: throat, jaw, cheek, then over to lips where they joined in a deep, heat-filled kiss.

They took turns gently sucking at each other’s lips, Sherlock parting to take John’s lower lip in his before letting go and John kissing into the lovely cupid’s bow above Sherlock’s. And in the middle of it all Sherlock began rutting, slowly rubbing himself into John’s lap, his fingers increasing the pressure of their equally leisurely circles on John’s gills. 

It was all very gradual, no rush, just even movements. John began meeting Sherlock with his own hips. They undulated together, their hands eventually forgetting about gills to clutch at other surfaces, John’s on Sherlock’s hips, fingers splaying across Sherlock’s clothed arse. Sherlock’s arms went around John’s shoulders, holding his head close with one hand curled around the back of his skull between him and the wall. 

The sensuous rutting continued like that for long minutes, Sherlock resting his forehead against John’s as their breath began to warm the air between them. John saw those pale blue eyes hooded and watching, watching what was happening between them, the bulges of their clothed erections pushing against one another, the rise and fall of their stomachs and chests as they panted for breath. 

All of it was intense, as slow and calm as it all was, just the heavy push and pull of their hips building the orgasm up and sluggishly taking it away from John like waves rising and falling on the beach, until Sherlock took control and decided to finish. He drew one of his arms away, tracing long webbed fingers over John’s shoulder and the gnarled scar there. With a particularly sinful smirk he drew away and licked his fingers. John could only watch, out of his mind on the steady, heady pleasure, mesmerized as Sherlock’s tongue traced the webbing between his first two fingers with a teasing glint in his eye.

“You wicked fish,” John murmured with a smirk of his own, still rolling his hips to the rhythm Sherlock set.

“Wicked, am I?” Sherlock’s voice was so affected by his arousal the vibrating sound made John’s cock throb. And then that spit-slicked hand skated down John’s belly and into his pyjama bottoms, wrapping firmly around his cock. John’s breath left him all at once at the sudden contact, his head rolling back to stare at the ceiling as he groaned. Sherlock grinned as he pumped John at the same pace as before, a long stroke up gathering the foreskin around his glans and tugging, then a long stroke back which revealed the head to the air. Sherlock shifted his hand so that John’s cock pushed between his fingers and past the thin, stretchy, skin between them. The webbing felt so different.

Sherlock leaned forward, pinning John in place with his chest as he let out a dark aroused chuckle, realizing what his voice did to John. The movement also trapped Sherlock’s hand between them, John pushing his cock through that webbed fist a little faster now as he panted towards his finish. Sherlock continued to rut against John’s hip, his speed increasing with John’s. 

Very suddenly it was all over. Sherlock’s lips locked to John’s, swallowing his impassioned moans and breaths and a dam broke as if the whole giant aquarium shattered and the water flooded out, a tsunami wave of pleasure. His eyes slammed shut and his whole body tensed while Sherlock continued to milk his cock, smearing John’s come over his palm. 

As John relaxed with a satisfied, happy sigh he realized that Sherlock was still at it, still grinding into his thigh, still panting. The hand on John’s cock had halted but kept a hold of the softening organ as Sherlock continued to thrust, a thin whine escaping his lips. His other arm’s grip shifted and John found his face shoved into the crook of Sherlock’s shoulder and neck. John smiled, brain fuzzy with the lingering effects of orgasm, leave it to Sherlock to need a bit of a hand and not ask for it.

Sherlock’s movements were bordering on frantic compared to his earlier lassitude, as though he felt like he needed to come right then and there along with John but the friction of rutting was not doing it. John let out an easy bubble of laughter into Sherlock’s neck and kissed him there. He moved one of his hands to Sherlock’s belly, feeling the hitch of breath as John laid his palm on the flat plane as Sherlock had done to him and then slid it down into Sherlock’s trousers.

John barely had time to feel the hot, hard length of him in his palm before Sherlock let loose a strangled gasp. He wrapped his hand around Sherlock’s cock and gave a couple of quick strokes. One long pull and Sherlock froze above him, hips stuttering into John’s fist as he came with a deep groan.

They both held that position for a long moment, Sherlock huffing lightly above John until he finally realized his hand was still on John’s softened penis and extracted it, flopping on John afterwards. 

“Oof, Sherlock, you’re not light,” John grunted, trying to retrieve his own hand from Sherlock’s underwear.

“Horrible pillow talk,” Sherlock grumbled sleepily next to John’s ear, giving said ear a small peck. He did shift though, rolling off, but staying snugged up to John’s side. The quiet returned as both bathed in the endorphin glow of orgasm. John was almost convinced Sherlock had fallen asleep until he spoke quietly right into his ear again, making John startle.

“Didn’t particularly plan that either,” Sherlock whispered with an audible grin.

“What do you mean?” John asked, tensing, had he done something he shouldn’t have, something Sherlock didn’t want?

“Meant to kiss your neck a bit, kind of escalated from there. Who would have guessed gills would be so sensitive,” Sherlock said with a low chuckle, kissing John’s shoulder and neck, over the gills and up to the spot just below his ear.

John relaxed again at that with a laugh. “Yeah, escalated a bit,” he admitted turning his head to meet Sherlock’s lips in a soft kiss. “Escalated to a good place.” With that they did finally sink into silence, John gazing sleepily into hooded blue eyes until they drifted to sleep, content and wrapped up in each other’s arms.

The new watch’s alarm wasn’t nearly as bad the next morning. It was still obnoxious with its staccato beeping but at least it wasn’t blaring through a few layers of hangover headache. They woke together, John kissing Sherlock before untangling himself from his arms. They continued with their normal routine of getting undressed and into the water, both grimacing as they peeled away their soiled underthings gone a bit crusty and disgusting in the night.

“Should have stripped out of these,” Sherlock mumbled looking down at himself. As pleasurable as the night had been, the feeling of come crusted into his pubic hair was not even remotely pleasant.

“I sort of pity the aide Mycroft’s got bringing us clothes,” John said, tossing his things into the pile with Sherlock’s. 

Sherlock simply dove into the water, cleaning himself off there, and John followed. And so their day continued. They twined around each other, sharing a few more kisses before the transformation happened again and they were stuck as fish for the day.

The next few days were far more enjoyable; their newfound relationship giving them something to do with their night time hours beyond the dwindling amount of research Sherlock could do on the computer. There was only so much even Sherlock could do with nothing to go on, so he would maybe solve a couple of cases from his website, then grump for a little bit about not being able to figure out this fish problem, before John would lead him away from the screens and they’d cuddle up in their alcove for the night.

It wasn’t all handjobs and frotting every night. After that first leisurely session, they mostly curled together snogging and touching. There were a couple of handjobs, yes, but their newfound closeness seemed to appease both of them, being able to caress and hold and kiss seemed satisfy Sherlock, and John found he didn’t mind either. He’d had a more active sex-life when he was younger and there’d been a terrible dry spell coupled with loneliness after being wounded, the orgasms were so good but wrapping up in Sherlock’s arms left him perfectly content too.

“You would like to do more, wouldn’t you?” Sherlock asked quietly as they snuggled one evening. It took John a moment to realize what ‘more’ meant. 

“Well, of course I would, but I’m fine with this too,” John replied, squeezing his arms slightly around Sherlock’s chest from where he had taken the big spoon position. There was a moment of quiet while John considered what exactly he would like to do with Sherlock. “It’s not like we have all the things we’d need anyway,” John reasoned with a small snicker. Sherlock just hummed a reply and continued to trace his fingers over John’s knuckles.

John felt that Sherlock might be up to something just before they transformed for the day. For the first time he could remember he woke up and Sherlock was not wrapped around him like a starfish on a rock. He wasn’t left to wonder where he’d gone for long though, since Sherlock appeared at his side, shaking his shoulder and telling him the watch had gone off. And so John simply shrugged off the disappearance as Sherlock being Sherlock and followed him to their tank, sharing their usual morning kisses over discarded clothes before sinking into the water for the day.

Sherlock stayed close to John all day that day, rubbing up against his sides and being overall as affectionate as a large tuna could be short of trying to spawn with him. John tried not to think about that too much, he wasn’t even sure how that process even worked and, even after months in a fish body, John didn’t feel particularly comfortable figuring out what ejaculating as a fish would even be like. Sherlock could try if he wanted to though, John figured, a little surprised he hadn’t seen Sherlock give it a go over the course of the last few days.

That night when John turned back into his normal self he happily found out what Sherlock had been up to that morning. He was ambushed coming out of the water, Sherlock grabbing him and hauling him out and onto something soft before John had the chance to peel the gel off his eyes and ears. But he felt Sherlock on top of him, the tall figure straddling him and sealing his mouth over John’s. 

“Sherlock what’s going on?” John sputtered, much as he enjoyed the kiss and the slippery naked man on top of him, not being able to see at all was a bit disconcerting. 

Sherlock leaned in close to the point John was laying flat on his back and put his mouth right to John’s ear. “More,” Sherlock rumbled simply, as he peeled away the gel over that ear. John felt the other ear freed as well and waited for Sherlock to clear his eyes. 

“More?” John asked with a laugh.

“Something different,” Sherlock said into his other ear, nipping at the earlobe there before rising up to sit over him again. John felt those long fingers settle, splayed wide, on either side of his neck and then gently trace their way down his torso, over collar bones, across nipples, down his belly, tracing through the natural slick jelly substance that covered their bodies every time they changed back into humans. Sherlock slid back a little to sit on John’s thighs and took John’s cock in hand. He gave it a few smooth strokes to bring him up to a good solid erection, not that John needed the help, really.

“May I at least see you while you do this ‘something different’?” John chuckled breathlessly, hips pushing up into the slickness in Sherlock’s palm as he rubbed the underside of John’s cock up from root to tip, pressing it into his belly.

Sherlock almost seemed to consider it for a moment, pausing in his movements with a finger resting on the glans. All of John’s focus went down to that one finger when he felt it start to circle the soft spongy tip again, just barely slipping under his foreskin as it circled, and oh that was an interesting feeling. “Yes,” Sherlock finally purred, and John almost missed it, so concentrated was he on that small sensation.

He abandoned John’s penis to lean forward and help him remove the gel from his eyes and John finally got to look up into Sherlock’s face, which descended and claimed his lips again in a deep kiss. 

“May I fuck you?” Sherlock asked quietly as he kissed his way down John’s chin to suckle at his throat.

John huffed a small laugh. “We haven’t got the things for it,” he replied, tilting his head back.

“Mmm, yes we do,” Sherlock replied tracing his fingers out and down one of John’s arms to entwine their slick fingers with a bit of a squelch that shouldn’t have been nearly as erotic as it was as he realized the implication.

“Condoms,” John choked out.

Sherlock’s head nodded to the side. “From the men’s restroom upstairs,” he murmured, working his way down to nibble at a collarbone, then further still to John’s left nipple.

John turned his head to see that the soft thing they were lying on was a blue mat and beyond the edge of it was a small pile of condoms, John laughed at the sight, turning into a small moan as Sherlock reached his chest and decided to run the broad flat of his tongue over a nipple. “You’ve put some thought into this,” John chuckled looking down at the black fluff of hair working over his chest.

Sherlock hummed up at him, mouth still occupied, before he propped himself up on his elbows and looked down at John’s pectorals as if they’d offended him. John watched those intense blue eyes scan over the scarring on the shoulder nearby and a smile curled on Sherlock’s face. He dove down for the other side, the right nipple, and actually got a reaction from John there, a laugh, not quite the one he was expecting but better. Sherlock smiled as he took the nipple between lips and tugged a little.

“Never been really into that before,” John confessed, letting out a small moan anyway as Sherlock gave up with his mouth and pinched with thumb and forefinger. 

Sherlock slid backwards deciding to pursue more erogenous regions of John’s body. He pushed his knees between John’s, who parted his legs so Sherlock could kneel between them, and buried his face in the base of John’s cock,mouthing at the spot between balls and shaft. John’s breath left him at the sudden feeling of lips and tongue, oh yes that definitely felt good.

John tried to stay still as Sherlock mouthed his way up his cock, using his hand to tug the foreskin back and reveal the spongy head before kissing the sensitive fraenulum. John watched as Sherlock lightly pressed his lips to the very top of the glans, barely fitting his mouth to the shape and letting his tongue tease at the slit there before backing off again, John let out a groan.

“Oh, don’t tease,” John plead, his hips twitching up into the fist Sherlock still had closed around the base of his cock, while Sherlock sat up and oh so gently began circling one long fingertip around the corona, circling on and on and on. John heard a dark chuckle from Sherlock and felt it in his balls as Sherlock bent again to mouth at them, pinning John’s cock to his belly out of the way as he lipped the delicate skin of his sac.

Sherlock’s freed hand reached down to grip John’s ankle, slowly drawing that hand up the length of John’s leg up over his thigh and the dusting of hair there, gathering as much of the slick substance on his skin as he could into his hand. John let out a relaxed sigh as he felt Sherlock’s mouth roam to the side, kissing at the crease of thigh and hip.

“Can I?” Sherlock asked quietly, trailing his slick fingers up the inside of John’s thigh. John barked a small laugh as he looked down into those very aroused eyes.

“Of course, come on, more,” John said, pulling his knees up a little to give Sherlock better access. Sherlock smiled, planting a few more kisses and nips into the skin of John’s hip as he kept those fingers going up the thigh to press at perineum and hole, spreading the slick and rubbing it in along with what was already there. 

That first finger slid in easily, the gel doing exactly what they both hoped it would do. John gasped at the different feeling, that one webby finger pressing in and wiggling, the webbing stretching against the rim of his hole adding in an interesting sensation. Sherlock worked with that, stretching and rubbing, preparing until John said quietly, “more,” and he added another, creating the stretching feeling John remembered, no pain, just a fuller feeling maybe a mild twinge, oh the slick was really doing its job well. 

And Sherlock nudged at his prostate, soon as he had two fingers to work with, and John felt the zing of pleasure as Sherlock pressed upwards and slid over the bump there. John’s hips lifted at that movement and the soft smile on Sherlock’s face curled into a particularly evil grin, crow’s feet forming at the corners of his eyes. The next moments were quickly filled with a litany of soft ohs and moans. John’s legs fell open further as Sherlock positively attacked that one little spot, playing his fingers over it, adding exterior pleasure to the mix by pressing at his perineum and stimulating from the outside as well, or moving up and rubbing John’s twitching cock in time with the motions of his fingers. A third slid in smoothly and by then Sherlock had John gasping on the mat, head tossing side to side, hands clenched into the foam with nowhere else to put them.

“More, Sherlock, more,” John panted, hips moving to meet those talented fingers, with a slightly frustrated groan as those fingers slid away.

“Fuck,” John heard Sherlock hiss quietly, making him look up at the slightly desperate tone. Sherlock sat there looking down at himself, at a somewhat flagged erection. John’ chuckled and for the first time since they started actually sat up, ignoring the wet squelches the motion produced.

“Got a bit stuck in your head huh?” John asked softly, bringing a hand up to Sherlock’s face, seeing the slight panic in those blue eyes as they locked onto John’s. "I can help with that,” John said huskily into Sherlock’s ear.

He shifted his legs, wobbly as they were from Sherlock’s attentions, till he knelt front of Sherlock, kissing him hard and deep until Sherlock himself was laying down on the mat, John balanced over him on hands and knees. Sherlock’s newly hardened cock poked up into John’s belly after the thorough snogging. He rutted against Sherlock for a moment or two till he had him good and panting as well.

“Wanna do it like this,” John spoke almost into Sherlock’s mouth, lips barely parting from his. 

Sherlock nodded with a groaned, “uh-huh,” watching John lean over and pull a condom out of the pile, ripping it open. 

John smirked down at him. “Let me try this,” he said, and then the condom was in his mouth. John’s mouth descended on Sherlock’s cock, and Sherlock stopped breathing for a moment as John swallowed his cock down in one easy motion, coming back up leaving the condom in place, sheathing him. John chuckled. “Haven’t done that in a while.”

The chuckle turned into a laugh as John watched Sherlock impersonate a goldfish, looking up at him. John wasted no time though, gathering up some more of the slick from Sherlock’s stomach and spreading it over his condom-wrapped cock. He shuffled forward, straddling Sherlock’s waist, Sherlock’s long cock bumping up against the curve of John’s arse. He couldn’t help but smile at the feeling.

Sherlock’s brain seemed to catch up with what John was about to do and those large hands came up to grip John’s hips as John reached back for that cock, raising up on his knees and slowly sinking onto it with a long sigh. Sherlock let out an equally pleased sounding groan at the same time, hands squeezing into John’s hips until he was fully seated in Sherlock’s lap.

“Oh, oh, good,” John panted, feeling the stretch as he finished sinking. He took a moment to just sit and feel before he finally moved, leaning forward and slipping off a little to kiss Sherlock’s open mouth. “Y’can move love,” he said, smiling at the shattered expression on Sherlock’s face.

And move he did. The moment John gave him the go, he started to rock his hips up, John just kneeling and letting him thrust up into him as he started skating hands over Sherlock’s chest, playing with nipples more sensitive than his own, scrubbing hands down his neck over his gills, leaving light red trails with his nails over Sherlock’s pale pectorals and ribs. Until Sherlock gave a particularly hard buck that managed to hit his prostate just right and John let out a low moan, rocking back to meet the thrusts now to try and hit that again.

“John, oh,” Sherlock cried, hands moving up from John’s waist, clawing up John’s back to pull him closer into a veritable bear hug, pinning John’s cock between their bellies as Sherlock began kissing and sucking his neck. And then they were rolling, John gasping happily as Sherlock rolled them over to get a new position.

Only there was a sudden drop, apparently Sherlock with his sex-addled brain had forgotten exactly how close to the water they were. Ah, but gills. Sherlock didn’t seem to give a damn that they were sinking into the aquarium tank, he just continued kissing up the side of John’s neck, clinging to him and thrusting away, not once disengaging. John clung onto Sherlock as well, the shock of abruptly being dunked into the tank dissipating slowly. He pulled Sherlock’s head away from his neck, making him open his eyes. Sherlock looked around him, his eyes reading ‘oh hell’ very clearly, but the hard cock still in John’s arse saying ‘who gives a shit, we can breathe, keep fucking.’

John rolled his eyes and pecked Sherlock on the cheek. Sherlock grinned and tightening his arms around John’s chest, gave a particularly pointed thrust that cried, ‘let us continue.’ John gave a mute laugh of surprise and squeezed his arse around that hard cock, making Sherlock’s eyes close in pleasure again. They ended up on top of the statue in the center of the tank, the flat top of the moai head big enough for John to lay back on and Sherlock to kneel and thrust into him. They kissed, and John laughed at the silliness of it all, them fucking underwater as large fish and tranquil sharks continued to circle around them. It was like a thing that happened in strange wet dreams. Sherlock seemed to love the laughter, holding tighter as he fought to gain speed and force in the water.

Sherlock buried his head in John’s shoulder, back heaving and arching as his thrusts became erratic and a hand came between them to stroke John’s cock. But Sherlock abruptly stilled, and John could almost feel him coming as he went rigid over him, biting John’s shoulder, fist pausing on John’s penis. Everything halted for a moment, nothing moving but the gentle sway of water around them until Sherlock relaxed and slumped onto John, weightless.

He didn't stop for long though, plush mouth sloppily kissing his way up the side of John’s neck, lipping the open gills there briefly. The hand on John's cock started moving again, with more intent, trying to bring him off. His other hand joined in, a couple dexterous fingers pressing up hard behind John's testicles, stimulating his prostate some more while he gently tried to thrust before his cock softened. Everything intensified in that moment for John and he clung to Sherlock, heels digging into his back as John's toes curled at a surprising spike in pleasure. Sherlock locked his mouth over John’s as he finally tipped over the edge and came as well, eyes snapping shut as pleasure mixed with the odd sensations of their submersion to create a curiously mind-blowing orgasm. 

They both drifted there, resting in the afterglow, until the small fish in the tank presented a problem. Well not a problem per say, they were just cleaning, pecking lightly at John’s belly and swarming around the area where he’d ejaculated. It was when a handful of them came for Sherlock’s softened penis still in its condom that they took offense to the cleaning and decided to move. Sherlock pulled the condom off and took it with them to the surface to discard.

The moment they broke the surface, John looked over at Sherlock’s wet head and burst out laughing. “Good God! I think that may have been the absolute strangest shag I have ever had!” He hugged Sherlock to him, even as Sherlock slung the used condom towards the concrete. Sherlock started chuckling too, their combined sounds echoing around the bare piping in the room; he pushed them back over to the edge, still chortling away. They flopped out of the water, laying side by side with their calves still floating.

“Oooh that really was amazing,” John said quietly once the laughter subsided. He rolled to the side to kiss Sherlock on the cheek. Sherlock looked smug at that, turning to kiss him back. “Any chance I could return the favor in the future?” John murmured reaching to run his hand over Sherlock’s belly.

Sherlock snorted. “Of course John,” he replied with a wide grin. The laid there smiling at each other for a long while, breathing and bathing in the post-coital hormones. 

Until John’s stomach decided to grumble and John shot upright. “The food! Sherlock we forgot about the food for tonight,” he cried, moving to get up, but Sherlock wrapped an arm around his waist and pulled him back down.

“Already taken care of, my dear John, I left her a note saying we’d be late tonight,” he said pinning John to the mat and lazily kissing an ear.

“You didn’t tell her anything, did you?” When Sherlock didn’t reply right away a small spark of embarrassment grew in his chest. “Sherlock Holmes, don’t you dare tell me you told that nice young woman we would be late because we were shagging each others brains out.”

“I did no such thing,” Sherlock said, obviously feigning hurt that John would imply such a thing. “I told her that I was studying the spawning habits of a particular type of fish tonight.” He admitted with a smirk.

John reached for one of the folded towels on the other side of the mat and swatted Sherlock with it. “Oh! You mad, mad, brilliant idiot,” John laughed, not meaning a word of the insults, as Sherlock pinned him down and proceeded to kiss him breathless again.


	7. A Fine Kettle of Fish

**Notes for the Chapter:**

> Thank you so much to beyonces_fiancee for betaing this chapter for me.

The next couple days following their foray into aquatic fucking were wonderful, well as wonderful as being stuck for half the day as a fish could be. Later that same night they’d gotten their food and then proceeded to curl up together to sleep the rest of the night away, only to awaken with a matching pair of hard-ons and the damn watch going off. Sherlock gave John a sly grin and a teasing grope before roaming off towards their tank. John soon learned what a tuna spawning looked like, as Sherlock changed mid-handjob and proceeded to ejaculate as a fish, muscles tensing and propelling him away, leaving John in a pale cloudy mess that the other small fish in the water happily darted through dissipating it. That had been interesting and almost unsettlingly arousing, and John swam to join Sherlock drifting along tiredly near the surface.

They ate, they snogged, they talked and cuddled and slept, and Sherlock seemed to have given up on figuring out what caused them to turn into fish, hitting dead end after dead end and coming up with nothing at all in way of an explanation beyond ‘probably magic.’ So it was now up to Mycroft to figure it out, and while they waited, there was no reason not to at least have some fun with their nights.

Two days passed and then their world got dumped on its head.

John saw the intruders first as they changed back into their human forms: the woman, the one he hadn’t seen in almost a week, was standing at the glass again. She stood flanked by a pair of rather sharky, familiar-looking faces. Her face wore a simple smile as she raised a hand and waggled her fingers in a wave, which looked anything but friendly when paired with the dead-eyed stares of the shark men to either side of her.

John darted for Sherlock, who hadn’t yet gotten out of the water but was heading that way. He caught his ankle, making him look down to see what John wanted. When John pointed to the window where the people had been, they were gone. A panicky feeling began to rise in John’s throat at that. Where had they gone? He definitely recognized the shark men, what if they got into the water with them? Would they be as deadly as the real sharks that surrounded them?

Suddenly a wall of bubbles crashed around them and John was looking up into a massive cast net, the weighted edges of which were quickly falling around them, forming a giant transparent dome like a jellyfish’s bell with Sherlock at its center. The net’s edges abruptly drew inwards and before Sherlock could turn and swim down towards John he was caught and hauled upwards by the sturdy nylon netting. John tried to grab at him, tried to catch the net and pull it back, but the person on the other end was stronger out of the water than John was under it.

For a brief moment John stared at the thrashing surface above him in horror. _What do I do?!_ John thought, looking up at the blurry shapes of their assailants through the agitation of waves. If all of them were up there--there could be the three that he had seen beyond the glass, there could be more--either way, he was screwed on numbers.

The decision was taken out of his hands as a fully clothed someone splashed into the water next to him. The crash of bubbles only obscured the person for a moment before John was grabbed by the thick hand of a shark man. John darted, trying to get away from him, and landed a slowed kick at his face that made the man let go momentarily, but the monster was almost instantly on top of John again with an inhuman speed in the water. This time he got both of John’s arms behind his back and wrangled him into a headlock, pushing up and forcing John to the surface.

Another pair of arms grabbed him and hauled him out of the water still deafened and blinded by the gel that always formed at the change: see-through in water, but shite on land.

“Sherlock, Sherlock!” John shouted, barely managing to claw the gunk free of an ear and eye before the shark man had both of his arms pinned, rough, nearly sandpaper-feeling, hands easily gripping John's slick skin. He dragged him across the concrete floor and into a kneeling position, roughly grabbing the back of his head to force John to look up at the woman he had brought him to. 

She had long black hair that draped over the shoulders of a expensive-looking suit and the moment he met her eyes he could see a dark glint in them. She could very well be his executioner and her eyes alone told him so. “Well aren’t you a specimen,” she said, a Irish accent strongly coloring her voice. She leaned down a little towards him, hands in her pockets, appraising him as though he were meat at the butcher's counter.

“Who the hell are you?” John spat, eyes darting to look around her for any other clues. Who else was there? What the hell happened to Sherlock? Anything that could be used as a possible weapon? Dark burgundy lips split into a predatory smile.

“Oh, but no manners at all,” she tisked. A hand lashed out and John felt dagger-like nails dig at his face as she smacked him, sending him reeling. Her hands had come out of her pockets and sure enough all ten digits were tipped with long black nails. In the next instant one of those pale clawed hands was stroking lightly through his hair. “I remember catching him, don’t remember you though, _I_ should be asking _you_.” He winced as her fingers curled and gripped into his hair harshly.

John didn’t reply, still gritting his teeth against the nails on his scalp. She rolled her eyes, “Fine, I am Jim, and you are?” Jim extended a black-tipped hand in a beckoning gesture. Her eyes took on an even darker murderous glint when John still didn’t talk to her and the hand in his hair wrenched back even further.

“Jim? Jim Moriarty?” Sherlock’s voice rasped nearby, John couldn’t see him right away, but he did get to see Jim’s face at the recognition. That creepy smile spread across her face, her eyes finally left his to look over at Sherlock, and the hand finally let go of his hair. 

Even with one ear and eye blocked he managed to spot Sherlock, he was still tightly wrapped in the netting, one of the shark men, pinning him so that he couldn’t struggle away, but he’d managed to clear his face so he could see and hear them talking. The net actually seemed to have helped in that respect, rough surface helping to rip away the slime. 

Just because Sherlock was held by the shark man didn’t stop him from wriggling in his grip, turning to better see the woman standing above them. “You’ve heard of little old me? I feel so flattered,” she replied, voice dripping with mockery, holding out the hand that had been in John’s hair. Another person standing behind her placed a towel into her hand. She stepped away from John and towards Sherlock, revealing another person, another woman, a very tall one. She looked more mysterious than Jim, wearing a long dove-grey wool coat with a high collar and buttons running up one side, a pair of black leggings, and grey boots that John could swear he saw the handle of a knife peeking out of. The upper half of her pale face stuck out from a dark grey scarf and from under a fringe of blond hair a pair of cold steely eyes bored into him. John would say she was pretty if she didn’t look like she would rip his throat out.

“Your name has been whispered in dark corners and alleys. I have been trying to find dear Jimmy for years and it’s you?” Sherlock said, looking Jim over. 

She dropped the towel she’d been using onto her shoe and suddenly viciously kicked Sherlock in the stomach. “It is _Jim_ not _Jimmy_!” she shouted at him angrily before she stepped back and her demeanor seemed to smooth over again in an instant. Sherlock immediately curled in on himself gasping for air at the swift kick just above his groin. “Now where were we? Ah, who the other fish is. Who is he then, Sherlock, your little friend here?”

John had tried to lunge for her the moment she kicked Sherlock, but the shark man holding his arms had him down in a second pinning him to the floor much like the other one had Sherlock. John stopped struggling when he saw the tall woman take a few steps towards him, the clack of her boots enough of a threat. “Is he a pet? Did your big brother give you a friend to play with? But that doesn’t explain why he turns into a fish... what have you been up to, Sherlock?” Moriarty continued questioning, in an unnervingly sweet tone as she crouched down near Sherlock, as though she hadn’t just attacked him.

“Bit him,” Sherlock grunted.

“Oooh kinky, and now he turns into a fish too? Like a werewolf?” Moriarty burst out laughing at him. The shark man holding him down started chuckling too along with her until she gave him a fierce glare that shut him up.

“Let me let you in on a secret,” she whispered. “I honestly don’t care. You’re both going to just be fish soon.” Those dark eyes slid over to John again for a moment before she looked back down at Sherlock. “He’s gonna be just another fat tuna fish, maybe I’ll have him stuffed as a trophy for someone’s wall or I bet he’d taste excellent prepared for a plate in Japan.” John paled at that. It had been funny weeks ago poking fun at Mycroft turning John into sushi. Coming from her lips the thought made John’s blood run cold. She would do it--turn him into fillet o’ John without blinking. “I’m gonna keep you though,” Jim said with a sadistic grin. “Put you in a nice big tank so you can swim round and round for me, bet your big brother would do just about anything to keep me from dumping you into a tankload of piranha.” 

John watched Sherlock’s eyes dart to him and for once John could completely read exactly what was about to come out of his mouth. “Not John--”

“Don’t you dare, Sherlock,” John interrupted, knowing exactly what was coming ‘Take me instead, leave him behind,’ and John was not having any of that.

“Oh? John is it? Johnny boy you’ll make for a really nice meal for somebody, or something, I could just have you dropped in the middle of the Atlantic ocean and let nature take its course too.” She started giggling a little. “So many ways to kill people when you have the power to turn them into sea creatures.” 

Jim rose, again quiet and composed. John was unsettled by the sudden shifts in her tone and caught himself actually wishing to return to their usual routine; he didn’t really mind the fish life if it meant not having to deal with the rather psychotic woman standing over him.

“Put them over there,” she ordered, pointing over to the stairs. Both of the shark men obeyed instantly, dragging Sherlock by the netting he was wrapped in and John by his wrists. “Sebbie, you have the restraints,” Jim said sweetly to the tall woman still keeping an eye on John. She pulled a handful of heavy-duty zip ties from her coat pocket and approached them, still not saying a word. John began to wonder if she could speak at all, his mind jumping to old mafia and pirate movies where tongues were removed to keep them from wagging about secrets.

They were both bound at the wrists and ankles. “You, over here,” Jim ordered to the shark man still keeping an eye on Sherlock. The brute let Sherlock drop to the floor and gave him a hard punch to the head as a parting gift, rendering Sherlock unconscious as his skull hit the concrete.

“Sherlock!” John called, trying to wriggle closer to him.

“I said over here, now!” Jim barked again, finger pointing to a spot right next to the water. 

The man grunted and went to stand where she pointed. Jim extended a hand towards Sebbie. “The book, dear,” she said pleasantly, looking up at the taller woman. ‘Sebbie’ popped open the buttons of her long coat and pulled a worn-looking book from inside. From what John could see of it, it didn’t just look worn, it looked old: like some ancient being had crafted the thing from dried leather, bits of sinew, and paper. It looked like it had been dunked in water at least a few times, wrinkled and warped as it was. The thing gave off an unhealthy sounding creak as Moriarty cracked it open in front of her and turned to the man at the water’s edge. The book began to emit an eerie blue glow the moment Jim opened it and it only got brighter the longer the pages stayed parted.

“Strip,” she commanded, and the man did as told instantly, removing everything and, when Jim added, “Today,” moving even faster, ripping the buttons off his shirt in his haste. John got an eyeful, the man’s shark markings even more apparent naked, a definite line outlining the area of his belly that would have been stark white on a shark but on him looked like a strange tan line. John snorted, holding in a shocked laugh when he realized that the shark features had extended to the man’s genitalia: where a shark’s claspers would have been, a pair of flaccid cocks hung side by side.

If John hadn’t already been the subject of some crazy mystical shit over the past few months he would not have believed what happened next. She began reading something off the pages, a language John couldn’t even begin to recognize, but he could see the shark man’s face fall as she started, a look of horror crossing his eyes. 

The blue light glowed even brighter and John suddenly remembered what Sherlock had told him he’d seen before he became a fish: dark hair and a blue light. John could almost hear a dull hum in the air, a dark droning noise like nothing he’d ever heard before, and the light suddenly arched away from the book. Like a finger of electricity from a coil, it jumped from the book to the man’s forehead and engulfed him. With a single wailing scream the man disappeared into a massive ball of blue light, not that he was engulfed in it but his very edges seemed to warp and blur looking less humanoid by the second. His form became spherical for a shrieking moment before parts elongated and stretched, and the scream died till only the hum was left. The light began to dim and all that was left in the space the man once occupied was a fully formed, writhing, grey-skinned, shark. 

Jim snapped the ancient book shut and the humming ceased completely. She stepped forward and, with one foot, shoved at the large shark’s side. The flailing creature rolled with the kick and went right into the water, where it swam away.

“Stupid disobedient prick,” Jim grumbled, turning around and handing the book back to ‘Sebbie’, leaving the discarded clothes by the water. She crouched down next to Sherlock and lifted his head up by his hair with a small curious hum letting it flop back after a moment. “You, pick him up,” she ordered at the remaining shark man, who was still glancing nervously at the water to which his comrade had been returned. He scrambled to meet her orders instantly, hefting Sherlock’s limp body up off the ground easily and slinging him net and all over his shoulder. John was thankful that Sherlock’s head didn’t leave the concrete with a bloody patch.

“Sebbie dear, I need you to carry the other one for me,” Jim said, once the other woman had finished buttoning up her coat again. Sebbie looked down at Jim, the coldness in her eyes melting somewhat.

“But my coat,” a slightly rough British voice murmured behind that scarf. John’s eyebrows shot up, the woman could speak.

“I’ll buy you a new one if he ruins it, dear,” Jim replied, slipping back into her sweet voice again. She leaned up on her tiptoes and pecked Sebbie on the cheek. John watched as the tall woman’s icy features melted even further into a fond smile.

“Alright, my Jim,” she replied, bending down and pulling her scarf away to kiss Jim’s forehead. It all would have been very sweet to John if the couple in front of him weren’t about to take him somewhere and turn him into fish fingers. 

Sebbie did as Jim had asked, and John soon found himself tipped belly-down over her shoulder. He watched the floor and familiar surroundings pass by while trying to think of a way out of this. Wherever they were going was not remotely good and Sherlock was still completely knocked out. Then it struck him: Sherlock was the one that was safe; it was only John they wanted to kill off. Jim had said she wanted to keep Sherlock around. If John could get away, if he could alert Mycroft. Yes, Mycroft could help. Now all John had to do was get away from the scarily strong Sebbie.

He looked down at his wrists together in front of him and the idea struck: break the ties. He knew how to get them off and the shark men had been dumb enough when binding them to put them in the front and no double up. Now he just needed the opportunity to get loose. Which came sooner than he thought, as they ascended the stairs and pushed through a door into the cool night air. 

They were in the service area at the center of the county hall building above the aquarium, and there right in front of the door sat a plain white van, the side panel door already sitting wide open. Sebbie bodily threw John into the back of the empty van, John landing painfully with a groan on the bare metal floor. The shark man carrying Sherlock crawled in behind him, inelegantly flopping Sherlock down against the wall, where he slid sideways, his face smushed against John’s knee. 

Sebbie and Jim took the two seats at the front, Sebbie driving. Now was his only chance-- the shark man was facing away from him. John righted himself, his back protesting against the back doors of the van, and took the tail of the zip tie in his teeth, pulling it as tight as he could before he jammed his elbows back against his sides. The tie didn’t break on the first try, but the second jab worked, the tie snapping audibly. The van began to move and John, adrenaline pumping like mad now that he had a chance to get out, reached down and with a couple forceful yanks snapped the ties at his ankles.

“Oi!” John looked up to see the shark man turned to face him, but John didn’t waste time being frightened of the fact that he’d been spotted. He reached up and grabbed the handle behind him. With a pop the doors flew open and he realized he hadn’t thought that part through, as he tumbled backwards over the bumper of the van that was definitely gaining speed.

“He’s getting away!” The man shouted from inside the van. John was a little more distracted by the sheer amount of pain his bare back was in as he landed on the asphalt and skidded slightly. He didn’t have time to stop though as he sat up and saw the van’s brake lights flash red in front of him. 

His brain screamed _Get away! Get away! Get away!_ the moment he heard the driver’s side door clunk open. And he ran, got his feet under him and sprinted for the door they’d come from. He didn’t care that he was leaving the crisp cool air of the outdoors behind again and returning to the depths of the aquarium. There was a murderous woman with far longer legs, who could probably outrun him easily, pursuing him.

John ignored the pain in his back as he vaulted down stairs and burst through the doors back into the aquarium proper. He could hear Sebbie behind him. She didn’t shout after him or make any threats, all he could hear were her footsteps following him, and that was even more terrifying than if she had been yelling. And then he heard a bang in the silence. He skidded around the corner of a hallway and turned wide eyed to see a crumbling bullet hole in the concrete wall where he’d just been. _Shit! She’s got a gun!_ John’s thoughts cried, amongst the swirling thoughts of where to run. 

John continued to wind his way through the aquarium, he could still hear Sebbie behind him. But it was only a matter of time before another bullet whizzed by. The shot hit the fish tank next to him, piercing the thick acrylic front and sending water spraying forth, catching John in the mess and making him stumble and fall.

The view as he rolled over, hissing as the salty water came in contact with his road-rashed back, was like something out of an action film. Moran stalked towards him gun still drawn and pointed right at his head. She appeared through the spray of water, any sentiment for her coat completely gone now as she stared him down from behind the barrel of her pistol. John shuffled backwards, hitting a wall almost instantly. His heart thudded in his chest, panic and adrenaline making the beat almost painful as he stared up into those cold steely eyes. 

A small glimmer caught his eye in the dim blue light of the hall, the knife, the handle at the top of her boot. His eyes flicked to it only briefly before focusing again on the muzzle in front of him, ready to blow him away. John watched her stand there for a moment, her nostrils flared as though she could smell the fear rolling off of John’s skin. Sebbie’s scarf had become dislodged during their chase and John watched thin lips open in a smile, revealing slightly pointed teeth, just like the shark men’s. _Oh God she’s one too!_ a panicked voice shrieked as John’s eyebrows rose towards his hairline. She wasn’t pretending to scent fear, he would bet money that she was smelling his blood on the air from his open wounds.

The barrel of the gun nudged his temple, snapping him out of his thoughts. “Got you,” Sebbie said quietly, grinning wide at him. And then the gun clicked, John flinched, and his life flashed before his eyes, his last thought being that he never got to kiss Sherlock again and say goodbye.

But nothing happened. The pistol lifted away from his head and Sebbie made a frustrated noise. The gun had jammed. John didn’t give her a chance to try again. He lunged towards her legs, roughly ramming into her as he grabbed for the knife handle. As she fell to the floor with a snarl, dropping her gun, he came away with a dagger about the length of his hand. Sebbie didn’t stay down for more than a second, though, and she was coming at John again. Out of pure reflex, he struck out with the dagger, slicing at her in an attempt to keep her at bay. The knife caught her face.

She recoiled instantly, shrieking. John had managed to slash her across the nose, a bloody red line bloomed stretching from cheekbone to cheekbone the tail end angling down her right cheek. John almost felt sorry for her as she covered her face screaming. Almost. He threw the knife down and ran, her wails following through the quiet halls along with the splash of water from the broken tank.

He did not stop until he reached the gift shop where he nearly ran into Emma. God, he’d forgotten all about her and their nightly meal. The moment she saw him her jaw dropped. John didn’t really blame her. He was panting, naked and wet and bloody, a far reach from suitable to be seen in public.

“I need- I need a phone,” John panted, trying to breathe, looking behind him just in case Sebbie had somehow managed to follow. “And I need to hide.”

She hesitated, and for a moment as he watched her eyes take him in, John worried she was either going to faint or run screaming for the police. 

“Christ!” she swore quietly, wide-eyed, looking over her shoulder towards the hall out. “Yes... Yes, come on, explain once you’re covered,” she said, looking around her for something. She pulled a souvenir beach towel off the rack and gave it to John, who wrapped it around himself as he followed her out. 

Of course the rest of the employees at the McDonald’s upstairs were unpleasantly shocked by his battered figure. They hadn’t seen him in weeks since the shark men incident. Emma herded John around the counter and had him sit behind it for the moment, at least it was a hiding spot for now. She was gone to find a first aid kit when John saw something in the mirror behind the counter that made his blood run cold.

Sebbie, soaked to the skin and even more bloodied than he was, stood at the entrance to the restaurant, a wild crazed look on her face under the mask of blood and scraggly blond hair. The cashier next to John looked down at him with wide startled eyes, all of this was far beyond these poor people’s pay grades and John wished if he made it out of this alive he could make it up to them. John shook his head and pressed a finger over his lips, silently telling the cashier not to give him away. He watched Sebbie stand there in the mirror for a long moment, he could see her nostrils flaring as though she were trying to sniff him out beyond the cover of her own blood, and for a tense moment he thought she’d found him as she stared right at the mirror. But as suddenly as she appeared, she stalked off, disappearing from view, and John felt like he could actually breathe again.

In the distance he heard a phone ringing and someone picked it up. “Sir, there’s a man named Mycroft on the line, says it’s for you.” John blinked up at the manager who had the phone cord stretched over to him. He took it and put the receiver to his ear just as Emma returned with the first aid kit.

“John-- “ Mycroft started.

“Mycroft, we’ve got an emergency on our hands here, some batshit crazy crime boss that goes by the name Jim Moriarty just showed up, I don’t know where they’re going, I just barely escaped.” John’s tongue felt heavy in his mouth. He couldn’t describe what the hell had just happened fast enough. It was all a blur now that he sat down and really thought about it, but one thing stood out above all else. “Sherlock’s been taken, Mycroft, he’s gone.”


	8. In Pursuit of A Fish

**Notes for the Chapter:**

> Thank you so much justaphage and nautilicious for betaing this chapter.

Very quickly the restaurant was covered in agents clad in black bulletproof vests. John was sitting being treated by staff and someone who had appeared with a much larger first aid kit, when Mycroft strode through the doors and past the wall of black-clad people blocking it. He looked far less put together than John had ever seen him previously; his wispy hair was ruffled, his tie askew, he lacked the jacket to his three piece suit and had only a longer coat thrown over waistcoat and long sleeves. His appearance betrayed the calm look on his face.

“What happened?” Mycroft asked, the chill in his voice making the question a demand. John looked up at him, the medic patching his back up still working away with gauze and bandages, and took in a deep breath, trying to figure out how to explain the events of the previous couple of hours.

“Some psychotic bitch named Jim Moriarty showed up, along with the two men who attacked us a few weeks ago, and a woman she liked to call Sebbie, right at the same time we transformed. I’m surprised none of your cameras saw them.” John said, hissing as the person at his back pressed a particularly raw area over his shoulder blade where he’d taken the brunt of his fall.

Mycroft’s lips thinned further at that. “The surveillance system put into place around this building went down approximately one hour before your nightly changes.” Mycroft turned to level a frigid glare at the small army of people guarding the door behind him. “I was only alerted to the error a few moments before I placed the call to have one of the employees here check on you, only to find you were already here and injured. I don’t enjoy repeating myself. What happened?” he asked again, leveling his gaze back on John.

“They took Sherlock away, in a van. One of the men knocked him out, but I managed to get away. I don’t know where they are going, I just know that it was in an unmarked van and Sherlock was unconscious.”

“Anything else, any distinguishing marks at all? You’ve been living with my brother for months now, have you picked up any of his methods?” Mycroft asked, his tone clipped and tinged with an anxiety the man was certainly not willing to show. “No, of course not, small mind, thinking with your dick, you spent more time trying to woo him than to learn anything from him.” Mycroft sneered. Suddenly those cool eyes were similar to Sherlock’s in the way they scanned over him briefly before they turned away.

“Woo him?” John spat, coming from Sherlock woo had been sweet and a bit twee, but hearing it from Mycroft, dripping with such contempt, made him want to bash the man over the head with his own umbrella. He swatted away the medic’s hand which was dabbing at the scratch marks on his cheek from Moriarty’s claws and finally stood up, clutching the beach towel around his waist. 

John was still shorter than Mycroft even as he straightened up in front of him, puffing up in pent-up anger and frustration at the circumstances. “Listen here, you arrogant prick! I’m only here because of you and your fucked up idea to protect your brother without actually informing the one doing the protecting! I’ve just spent the last months turning into a goddamned fish every single day and, when not a fish, being confined to the same building the entire time! I haven’t seen the fucking sun in months! I’ve been stuck on a diet of whatever ‘food’ McDonald’s can provide for me, no offence Emma,” John barely spared her a glance for an apology before he rounded back on Mycroft. 

“Tonight I’ve watched a man literally turn into a shark in front of me. I’ve been manhandled by a woman who is also a fucking shark of some kind in human form. I have fallen from a moving vehicle, which if you haven’t noticed, happened while nude. I have been shot at, and I have come about this close to having my brain splattered across the aquarium wall by that same murderous shark woman, who is named _Sebbie_! Yes, I have fallen for your brother, sue me! He has been the only company I’ve had for this entire fucking fiasco, I bloody love the mad arse I share my fucking fish tank with every day! The fact that my mind does not function on whatever supernatural plane the two of you do doesn’t mean a goddamn thing, I’m a fucking doctor, was a damn fine surgeon, fought in a war, and could fucking break you! I know right now that some nutjob who can turn _FISH_ into people and back has just kidnapped the man I fucking love, so either give me something to help find him or step the fuck off!” 

The restaurant had become deathly still and silent over the course of John’s raving but he didn’t notice until he stopped, breathing a little hard but feeling a bit better after letting the arse have a piece of his mind. If Mycroft was at all surprised by John’s bombastic reaction his face didn’t show it, he just continued to stare down at him. When he did move it was to reach into one of his coat pockets and pull out a smartphone. 

In the moment of quiet John suddenly realized what he’d just said. He’d said he loved Sherlock. He hadn’t even told Sherlock that to his face yet. A shrinking feeling squeezed John’s heart at the thought that if he didn’t manage to get Sherlock back to the aquarium before dawn he might never get to tell him.

“Sir, your clothes.” A voice interrupted his thoughts; one of Mycroft’s people was standing at his side, a bag of clothes held towards him. 

John took the bag. “Thank you,” he said quietly, still not moving from his place in front of Mycroft, who continued to fiddle with that damn phone. A still angry part of him wanted to smash the phone and demand Mycroft talk.

“We have a signal,” Mycroft said, and everything around them seemed to start moving again. All the guards and agents around them scattered, out the door in a flash and gone as quickly as they’d come, leaving the poor confused employees and manager behind the counter.

“What was that?” John ground out.

“Shortly after discovering my brother’s condition I had a tracking chip implanted into him, a precaution in case the people he had been tracking decided to return for him. A large bluefin tuna such as him would fetch a high sum at market, you understand.” Mycroft turned the phone around so John could see the screen. There on the display was a map of lower England with a small blinking fish icon moving very slowly southwards. John was very glad he hadn’t acted on that impulse to destroy the phone. He took the phone from Mycroft though, grabbing for it quickly and trying to look closer at where the little icon was going, zooming in further on the map and watching it update and move a little further south.

“I doubt he liked that very much,” John muttered, eyes never leaving the screen.

“I doubt he is even aware of its presence; I had it installed while he was a fish. As far as he knows the aquarists were simply performing health and wellness related exams on a newly acquired resident.” Mycroft replied pushing a hand through his hair in an attempt to smooth his appearance once more.

“How did you know that it wouldn’t hurt him when he changed back?” John asked finally looking up at Mycroft with a small stab of concern running through his mind. Mycroft didn’t answer right away, opting instead to straighten his tie and coat quietly. “Mycroft.” John said again with a little more threat thrown in.

“At ease John, it’s a small chip, barely the size of a pencil eraser, there was no risk involved, it’s already being used to track large endangered animals in wildlife reserves,” Mycroft said calmly and turned to leave.

“And where do you think you’re going?” John asked taking steps to follow him.

“To retrieve Sherlock, of course,” Mycroft said the ‘are you really so dim’ implied heavily in his voice.

“I am coming with you”

“You are staying here. As far as I am aware you still suffer from the same affliction Sherlock does wherein salt water becomes necessary come morning-”

“I don’t care. I _am_ going with you. I _am_ going to rescue Sherlock from that psycho, and if it comes down to morning time I will either die protecting Sherlock or you can try tossing us into the sea.” John cut Mycroft’s excuse off, he was going after Sherlock and that was that, if anything to tell the man he loved him at least once, before he was killed and possibly stuffed into tins.

They stood staring each other down for a long moment, eyes locked and both determined to get their way, John in his impromptu towel sarong, clutching a brown bag of clothes in one hand and Mycroft’s phone in the other. Mycroft finally sighed, bringing a hand to his face to massage the space between his eyebrows.

“Fine,” he murmured and continued on his way out. John followed.

The moment John stepped through the glass doors and into the open he couldn’t resist taking a deep breath of night air. He hadn’t been able to appreciate it before in his terror to get away from Sebbie and Jim. The cool fresh air felt and smelled wonderful after months of being inside, breathing the recirculated conditioned air constantly. John didn’t have long to enjoy it though, as he stuck close to Mycroft. 

The area in front of the aquarium in the shadow of the London Eye was still littered with tourists even at night, people hanging around for London’s night life, restaurants, the lights along Thames and the Eye and the bridge and parliament, some waiting for midnight to toll from the clock tower on the opposite bank. Regardless of his stature, walking among them in the nude save for a beach towel did manage to turn some heads to watch him go.

Thankfully the walk from the exit up the stairs to the nearest street was not a long one, and no one made any fuss over John’s appearance. A black car awaited them just around the corner of the building, and Mycroft ushered John inside. The car sped off the moment the door shut.

With a put-upon sigh Mycroft looked towards the window and said, “Put your clothes on.” John was slightly thankful for the polite head turn to grant him some level of privacy as he struggled into his things even though Mycroft had already seen him in the buff at least a couple of times.

Once John was dressed, jeans, shirt, and all he looked back at the phone tracking Sherlock. The little icon had shifted further down, already on the motorway and still heading straight south towards Crawley. “Would you please explain why you are not still with my brother?” Mycroft asked, breaking the quiet in the car.

“They said I was disposable, wanted to kill me at the first opportunity, but Sherlock they want alive and safe. That Jim woman, she said she wanted to keep him, use him as a bargaining chip of some kind maybe. I saw a chance to escape and try to get you and I took it, how was I supposed to know you had a tracker?” John said, waving the mobile in his hand. Said phone began to ring, cutting away from the map to the call incoming screen, and John handed it back to Mycroft.

Following a short and cryptic conversation the car was quiet again, and John had no idea where they were or even really where they were going, though he hoped that at least they were heading south after Sherlock. And then they stopped. John looked out the window only to see brown fencing with a gate number on it. 

He threw a questioning glance at Mycroft, who slipped his phone back into his pocket and proceeded to get out of the car. John followed and finally got an answer. “The London Heliport, mainly for tourists, but it’ll do,” Mycroft said walking toward the gate, which opened to reveal a small troupe of people similarly dressed to the ones John had seen secure the restaurant earlier. He followed Mycroft across the helipads out towards the Thames where a black helicopter sat illuminated by one yellowy light on a pad over the water. Four of the agents climbed into the back of it, two taking seats as the pilots, the rest stayed hovering near Mycroft.

“If you must go, you will be accompanied by my people. You will stay in the vehicle until they have secured the area, however.” Mycroft said imperiously, as though he had any control over John at all.

“We’ll see about that,” John mumbled, brushing past and following the others into the helicopter. The man he plopped down next to looked to Mycroft with a questioning face as John simply started buckling himself in.

Mycroft sighed, “Dr Watson will be accompanying you, protect him at all costs he is rather dear to my brother,” he ordered as the rotor blades began to turn, the engine revving and beginning to make the deafening noise that drowned out anything other than shouting. Everyone in the helicopter threw up an 'okay' hand sign as the roaring of the engine and spinning blades grew louder. John watched as Mycroft backed away and they became airborne, the helipad and the Thames dropping away below them and the London skyline appearing, pilots already following Sherlock’s tracking chip and heading south.

John briefly wished he had kept Mycroft’s mobile so he could continue to watch exactly where Sherlock was, hell even where they were even headed. He only knew south; he didn’t know where exactly Jim might be leading them, she might have even changed directions since John had handed the map back for all he knew. 

He let his thoughts wander for a while, focusing on nothing but the loud thrumming of the rotor above him and the rare staticky voices over the protective headset he wore. John looked around to the other people in black sitting around him quiet and still. A tiny scared part of his mind supplied that they probably didn’t care one whit about Sherlock, not like John did. The only reason they were going was because Mycroft apparently had an even more ridiculous sway of power than John had thought. They weren’t going because they wanted Sherlock back, they were just doing a job. If Sherlock weren’t Mycroft’s brother, John would almost bet Sherlock was a secondary mission on the way to capturing the kingpin Jim.

John continued to stew in those sorts of thoughts, swirling them together with horrible ideas of what Jim might do to Sherlock and just letting those fuel the rising urge to rescue and protect him. A voice came across the headset, “I have a location.” and in that moment John looked out the window into the darkness and wanted to leap and come crashing down on top of Jim, death from the fall be damned. But of course that would help no one so John stayed put, fingers clenching into fists over and over against his knees as he looked down into the pitch black countryside. Of course this would happen during a new moon, no white pale light illuminated the ground below, only the red and yellow little lights from cars and street lamps. John wished he had whatever night vision the pilot was using.

They were suddenly descending; all John could see were the lights of a city’s urban sprawl cut by sections of inky blackness until a turn revealed an industrial looking area below. Docks, with large warehouses and docked tankers, it became more apparent that the darkness beyond was water. They were somewhere on the coast, if they’d continued south, maybe Brighton.

The helicopter was rapidly moving towards one warehouse in particular, not well lit, just enough to show a nondescript old box of a building. As soon as they were down John wanted to tear off his belt and headset and be the first one into the building, but the other four beat him to it. Belts already undone and ready for action, they poured out of the little helicopter.

He watched the four agents go to work, drawing weapons and stalking towards the building in their bulletproof vests and gear. And it was in that moment John realized how woefully unprepared for this whole endeavor he was. As much as he wanted to burst in and carry Sherlock over his shoulder back to the aquarium, it just wasn’t going to happen, not in a button up and jeans and absolutely nothing that could be called a weapon beyond his own fists.

So, John resigned himself to actually reluctantly following Mycroft’s order to wait in the helicopter until the deeds were done and the agents returned with Sherlock. Then he could dote all over him and take care of any wounds to his heart’s content.

But the agents never came back. Time ticked by slowly and John continued to glance at the glowing green numbers of the digital clock in the cockpit. He looked out the windows at the ominously darkened warehouse scanning for any sign of movement, but there was nothing. A few minutes crawled along to ten, to twenty, a half an hour ticked by and John began to feel worry squeezing at his heart even more as no one returned. Surely a half hour would be long enough to locate Sherlock and come back. _But what if there’s a standoff? What if there were even more of those fish people waiting inside to ambush anyone who enters? What if they’ve all been captured?_ John’s mind started spinning scenario after scenario of what may be taking the professionals in bullet proof vests so long.

Then John saw it, a blue glow through a window high on the wall. A faint thing through the grungy corrugated plastic panel but definitely a blue glow. It flared, bright like a flash of lightening and then, almost as suddenly as it appeared, it vanished and the building was a dark shape again. That was enough to get John on his feet, screw the plan, screw the fact that he had no weapons, and screw Mycroft. John was going inside now, a glance at the clock again only spurred him on; forty five minutes was long enough in his book.

John was out of the helicopter and against the side of the warehouse next to a door in moments, sprinting across the barren area around the building with only the crunch of gravel accompanying him. He pushed the door open as quietly as he could and slipped through the gap into the unoccupied area he could see beyond. John crouched behind a box; now that he was inside he could hear extremely faint voices coming from the other end of the massive open room. The area he’d come into seemed to just be storage for god knew what, crates and boxes stacked and shelved all around with writing from any number of countries all over them.

He heard a splash, like a large object being dropped into a pool. That made John start moving towards the voices, and now the splash, remembering what Jim had said about fixing the curse on Sherlock and making him a full-time tuna. 

As John crept towards the noise he nearly stumbled across a handful of knocked out people along the way, all dressed and wrapped to the nines in scarves and hats and such. John wasn’t going to take the time to unwrap them, but it was a safe bet that under it all they had gills and markings and sharp teeth and belonged to Jim. Another large splash made him pick up the pace a bit.

“Shhh my dear, I’ll fix it right up,” John heard, following a particularly pained groan. He’d finally reached the area the sounds were coming from, a soft familiar blue glow shining over the wall of crates and shelves. “Come on Sebbie, take it off.” Jim’s voice cooed sweetly. John took a risk and peered around the box he sat crouched behind. 

John had trouble focusing on any one thing as he took in the sight. In the area beyond sat aquarium tanks, large ones, all emitting their calm blue light, all occupied and surrounded by scaffolding. In front of him on the ground, lay a pile of discarded black clothes and weapons. Near that on the floor lay a weakly twitching large silver fish, its mouth and gills flexing as it suffocated. Ascending one tank’s black metal scaffolding was one of Jim’s brutes, another large silver fish slung over his shoulder, John watched as he simply tossed the fish into the water. Jim herself was sitting near the base of one of the biggest tanks, Sebbie seated across from her, slowly peeling the scarf away from her bloodied face followed by her coat and shirt till she sat half nude before Jim. 

John couldn’t take his eyes off the pair once they landed there. Partly because seeing a naked shark woman was an intriguing sight; there were no breasts, no nipples, just flat muscled planes and faint dark tiger-like markings. _Still beautiful in a way,_ a reptilian part of John’s brain supplied that he quickly shook away. Also, partly because it was quite frankly bizarre seeing Jim acting so kindly towards Sebbie.

“There we are, now sit still for me,” Jim said, John saw her hand go to a book in her lap, the book, the old wrinkled thing that had turned the man at the aquarium back into a shark. It struck John in that moment just what happened to Mycroft’s agents as his eyes darted from the book to the fish on the floor that the shark man had just picked up and back. 

The book glowed, like it had before, and Sebbie’s face took on that same eerie electric blue hue. It grew and covered the rest of her head on down her neck to her collarbones and John watched as she obeyed Jim and sat perfectly still for her. The only movement was her hands clenching on her knees and her lips thinning into an almost worried looking lip bite. The glow increased in intensity and suddenly Sebbie’s features were warping, looking less and less human by the second as her eyes turned dark and her mouth widened and even sharper teeth appeared. Her short hair disappeared and her ears melted away, but her nose grew longer and more pointed. Her markings darkened into very visible tiger stripe bars covering her shoulders and back, and her skin overall greyed but her jaw and belly shone even paler and whiter than before. 

John watched with horrified fascination as Jim slowly shifted Sebbie into something even closer to a shark than a human, but not entirely. From the chest down Sebbie was still normal human with legs, but that face, which had been quite pretty despite the teeth and gills, had transformed into something like in a horror movie, a half formed thing of disturbing proportions. Sebbie’s hands continued to clench and unclench on her thighs throughout the whole process, and her chest started heaving, tooth lined crescent of a mouth open like the sharks back at the aquarium. 

Then the deep cut across her face lit up like a lightening bolt, obscuring her face momentarily as the glow reached a blinding level. That was the one moment John looked away. When the flash of light died down and he looked again, there was only a jagged pale scar left on Sebbie’s face. The terrifying morphed features slowly started disappearing again, blond hair returned, nose shrank, teeth returned to pointed human rather than a maw of needle sharp death, and markings faded back to more normal human skin tones. And in moments the whole process was done, the book was closed and there sat Sebbie, a new silvery scar spanning the width of her face but otherwise good as new. 

“There’s my good girl,” Jim crooned softly, reaching out to run a thumb along the newly healed skin on Sebbie’s cheek with a smile. 

“Mmm, not so pretty now,” Sebbie replied, leaning into Jim’s hand, but her eyes were looking to her reflection in the aquarium glass next to her.

Jim’s grip on her cheek seemed to harden slightly making Sebbie’s eyes focus on Jim instead. “Ah ah, none of that,” Jim told her, “you’ll always be my big pretty tiger,” she leaned in and planted a quick peck of a kiss right between Sebbies light eyebrows. 

John had to strain to hear Jim murmur, “and you know I like your battle scars, just adds to your lovely stripes,” they both chuckled at that, Sebbie nuzzling into and kissing Jim’s forehead. 

The private moment was shattered by a pained groan nearby, the pair and John all looked towards the source of the noise and John had to stop himself from gasping. There was Sherlock still wrapped in netting and tied to a pole on the scaffolding. He looked like he had been beaten to some degree in the time since John had last seen him. A large bruise was blooming across one cheek, another was beginning to darken the opposite side’s eye, a smattering of smaller ones decorated the rest of him, and his wrists and ankles where he was still bound by zipties were red. 

Sherlock was just covered in grime as though he’d been dragged through the warehouse wet, which was pretty likely. Considering they had been yanked from the water right after their transformation and had never gotten to clean themselves of the usual slime, John wasn’t exactly surprised to see the peeling, caked, and dried remnants of it, but it certainly didn’t help the whole upsetting image.

Jim rose with a put upon sigh, patting a grumbling Sebbie on the shoulder, and sauntered over to Sherlock. She put a finger under his chin and made him look up at her through still bleary eyes. “Awake now Mr Holmes?” She said loudly, causing Sherlock to flinch and pull his head away from her hand. 

It took all of John’s power not to jump from his hiding spot and go to Sherlock, get her away from him at least. 

“Well hello there,” Murmured a gravely voice that sounded like it was right behind him, John didn’t have time to turn before something solid connected with the side of his head and his face slammed against the box he was crouched behind. And the world very suddenly went dark.

John came around to the sound of moving water nearby, and for a moment he thought all of it had been a dream. The crazy crime lord, the shark woman, the kidnapping, all of it just a figment of his imagination. They had simply fallen asleep together in the aquarium and it had all just been a nightmare, the watch alarm would be going off any moment and they’d change into fish and go on with the routine.

Until the throbbing pain in his head caught up to him and John noticed the other aches, the scratches on his face, the road roughed areas of his back, and a new feeling of metal grating digging in down one side of his body. John didn’t even have to open his eyes to know that he wasn’t somewhere good. Also his clothes had gone missing, so to top the whole miserable situation off, he was naked again. 

“You’re awake now, I can tell,” whispered an irish accent near his ear, Jim. A part of John curled up in a tiny defensive ball at the sound of that sadistic voice so close to his head. “You hurt my Sebbie, you know what happens to people who hurt her?” John really didn’t want to know the answer to that question, considering what he’d already seen of the pair he was sure whatever it was wasn’t good.

His eyes popped open instantly as what felt like a dagger stabbed right into the middle of his old shoulder wound, a knife point digging into the bullet hole again with a force that made John gasp and writhe away. It was Jim’s hand, her sharp black nails. She was gripping into John’s shoulder and digging the tip of her thumbnail in as hard as she could, the other four clawing into the back of his shoulder along with it.

“They die,” She hissed at him, her face a mask of anger. “But I was already going to kill you, so now I’m going to play with you first. I was going to give you a relatively easy death, but now, now I get to do it slow. People will be finding bits of you all over the country when I’m done.” Jim told him, pressing harder and harder into his shoulder with her thumb.

“John, no,” John heard another voice rasp nearby, Sherlock. He sounded awful and John instantly tried to twist to find him, not caring about the torment being inflicted by Jim’s claws.

Sherlock was laid out, finally rid of the netting he’d been captured in, but bound in a new way with his arms twisted and bound behind his back from elbows to wrists and new cuts and bruises definitely blooming. John remembered the healing from before, Jim could heal those marks only to inflict them again, and what a horrific thought that was. “Sherlock,” John called throat tight. 

“Aw don’t want to see your pet hurt?” Jim cooed over at Sherlock, even as Sherlock tried to struggle against his bonds. “You know, this way you get to see him alive a little longer? He just slowly gets turned into bits, easy to remove pieces first.” Her grip on John’s shoulder receded and John let out the breath he’d been holding against the pain. But her touch didn’t go away, making John cringe again as one of those long black nails traced gently along his skin, down his arm, up his ribs, nearly tickling in its delicacy. “Fingers, toes, ears,” Jim’s hand came up to pinch the closest earlobe, tugging playfully even as she was threatening to remove said body part.

The full set of claws suddenly were tracing down, scratching over John’s pectorals, clipping a nipple in their path on their way down his belly. Like a snake striking, those fingers darted for his most sensitive bits and found John’s bollocks. Nails dug into the tender flesh of his scrotum and John couldn’t begin to suppress the surprised and pained yelp that escaped his throat even as she tugged his balls in a cage-like grasp. “Maybe something more _precious_ ,” she accentuated the word with another spine chilling pull, squeezing a little more. John was a paralyzed crab in her grasp, frozen in place, mouth open, and mentally begging that she not decided to suddenly act and castrate him then and there.

Thankfully, she let him go with a firm parting drag of nails on his thigh. John instantly curled in on himself, attempting to protect those vulnerable parts from further abuse and not caring about the drag of the grating on his side. A glance at Sherlock revealed a pale horrified face, unaffected mask completely slipping and falling away in fear for John’s safety. 

Jim let out a sinister chuckle at the pairs reactions, hammering home for John just how fucked up a situation they’d landed in, “Now you,” she said stepping over to Sherlock, “dawn’s nearly here and I want you to stay a fish when you change.” She grabbed his jaw so that he would look at her instead of John, “No we’re talking now, you and me, not him. You’ll see him later, put him him right near the glass when I start taking bits off so you can see it.” Jim said with a too-cheerful smile. “Sebbie my book dear.”

Sebbie appeared from beyond John’s field of view, still half undressed but seeming to not care as she offered the old book to Jim. “Stand him up for me dear if you would?” Jim asked and Sebbie did so, grabbing Sherlock and lifting him from the ground like he was just a sack of flour. Sherlock’s calm thinking mask was back in place for the most part, as he stood naked before Jim, arms still bound behind his back. John wasn’t fooled by it though. He could see in Sherlock’s eyes the way they kept darting down to look at him that Sherlock was panicking inside, that big brain trying to figure a way out of this if not for him, for John.

Jim cracked the book open and that damn glow started to well up from its pages again as she flipped through it. She stopped on a page with a happy little, “ah,” and looked at Sherlock, who began to glow as well.

“No, damnit, no!” John shouted from his place on the floor, writhing against the ties at his wrists. No way was he just sitting there and letting this happen, Sherlock was coming home with him as a man, fuck if he had gills and they were stuck at the aquarium, at least he would have a human form.

His yelling did nothing to stop the glow from spreading and covering Sherlock completely, Sebbie barely gave John a glance as she continued to hold up Sherlock for Jim. John continued to struggle, screw the pain as the ties dug into his wrists, fuck the grating abusing his front as he tried to get to his knees. His mind was a litany of ‘no, fuck you’ as he grit his teeth and pulled, trying in vain to break his bonds and stop the madness.

Sherlock’s pained gasp as whatever Jim was doing took hold was the final straw; with a mad rush of adrenaline and a massive pull, the muscles in John’s arms strained and the ties binding him snapped with an almost anticlimactically small pop. His arms flew forward and in a matter of seconds he was off the floor and charging at Jim with a feral yell.

Sebbie threw Sherlock to the ground to intercept John, arm darting out to grab the back of his neck and attempt to wrestle him to the ground. John was done, he’d had it with the pair of them and nothing was keeping him from Jim and that book. He countered with an elbow to her exposed gut, hoping that it would wind her like a normal human, and not only managed to make her crumple a bit, but staggered Sebbie to the point that a good shove sent her backwards into the blue water of the tank.

John refocused on Jim. Sherlock was encompassed in her glow and even though he was on the floor, his transformation was continuing. John realized he hadn’t actually watched what happened to Jim while she was working her magic, he’d always been focused on her subject. It was as though the light of the book had crept under her skin through her veins, her pale throat was covered in webs of glowing blue, her normally dark eyes were shining with the same electric blue light that surrounded Sherlock, and even her hair seemed to be giving off that ethereal glow.

The sight could only make john pause for a moment before he lunged forward; creepiness be damned, he needed to get that book away from her. The moment he touched it, her eyes locked onto him and with an almost supernaturally ear-piercing shriek she backhanded him, clutching the open book closer to her chest. He tried again barely fazed by the hit, Jim was no Sebbie, she didn’t have the same brute strength. This time he managed to get a grip on the book. Even as she wailed at him both with her voice and her clawed hand, John struggled to get the thing away from her. 

With a wrenching move John pulled the book free of her hands. The sound that followed was both frightening and deafening, like something from myth had been angered. Jim was like a deranged siren, her beautiful face twisted with rage and an inhuman shriek emanating from her as she flew at John. 

The whole situation was going to hell quite quickly as John turned to where Sherlock had been writhing, only to find a large fish had taken his place, a tuna twitching weakly at the water’s edge. Sebbie was emerging from the water just beyond, hatred for John burning in her eyes. Jim took advantage of John’s pause to get an arm around his neck, the other grabbing John’s free hand, twisting it behind his back. 

“Sebbie, gut him, gut him now,” She grit out right next to his ear.

John saw a small glint of silver in Sebbie’s hand, a wicked looking pocket knife, and he struggled all the harder at the sight of it in her hand, mind leaping to what she intended to do to him.

The tuna next to Sebbie however gave a great heaving flop and flail, strong tail knocking into her, making her fall gracelessly to the floor. Poor Sherlock continued to wriggle, sleek body bowing and writhing on dry land, battering Sebbie in the process until he finally rolled into the water. There was a brief moment of silence as all three of them stared at the tuna darting away into the water, as though, of all the insanity that had happened, that was the strangest bit of the night.

Sebbie did not take long to get up and retrieve her knife again. She began approaching John with the original intent to slice him open, revenge for the scar marring her face clear in her eyes. 

A couple of strange miracles happened in the blink of an eye. The first came in the form of a large flying fish. Sherlock, like a giant dark torpedo, came sailing out of the water right at Sebbie. His fishy bulk rammed right into her back and sent her lurching forward. The second came in the fact that the knife she’d been brandishing at John missed his belly and instead sliced into the cover of the book before dropping harmlessly to the floor.

Jim screamed as the book was damaged and fell away from John’s back as though she was in pain. He spun on her expecting her to surge back up, only to find that she was staying down, crumpled on the floor shrieking and holding her head. He looked from her to the book, to the knife, and over to Sherlock who was still lying across a downed Sebbie, tail twitching ineffectively as he tried to wriggle back towards the water. In the momentary pause John’s brain made the connection. 

He knelt down and took the knife and the book, the horrible leathery thing. John set it on the floor and took aim to run it through with the knife. Jim’s glowing eyes shot up to him and she screamed “No!” trying to dive for the book, but it was all too late. John brought the knife down and sank it through the cover and into the pages. 

Jim writhed away as though she had been stabbed, and John watched, mildly horrified by her spasming and twitching, even as he sliced into the book a second time. The glow under her skin and in her eyes seemed to intensify and she squirmed like a fish on a hook, still pleading for John to stop.

He finally gave up on the knife and decided to go at the book with his bare hands, opening it and just ripping out pages, shredding the thing in any way he knew how. Jim eventually went quiet, and she lay in a twitching drooling ball before him, eyes wide as she buried her clawed fingers in her hair. John decided to finish the tattered book off as he looked over at Sherlock, still unable to return to the water and suffocating. Taking hold of both covers, he prayed that this might somehow help Sherlock and tore, ripping the spine of the book in two.

If John thought Jim was deafening before, it was nothing compared to the almighty roar that accompanied the ripping of that spine. John felt himself thrown away from the remains of the book as though tossed back by an explosive shock wave. He landed against Sherlock’s wet side and could only stare as Jim herself levitated before him still curled in a ball, crying, pleading for mercy to an invisible force that had her like a kitten by the scruff. It wasn’t just Jim making noise, Sebbie next to him was screaming too struggling out from under Sherlock’s tail and scrambling as though to get away from some unseen threat, only to fall backwards into the aquarium. The whole warehouse seemed to echo with cries of varying volume, whatever was happening effecting all of Jim’s underlings at the same time. 

And then there was Jim and John watched wide eyed as her shape began to warp, as Sebbies had before. Her whole body began to change, the seams of her suit ripping and splitting as her body swelled and grew, her arms shortened, her legs fused, and her face, her face was the most terrifying change of all. Jim’s face began to elongate like something out of a monster film, the werewolf’s muzzle emerging from human features, her open screaming mouth filled with wicked serrated teeth, her cries changed pitch but not volume. Her long black hair seemed to meld into her skull and skin, wherever the strands lay they became like an inky tattoo on her flesh. Her skin greyed and spots formed, her belly and chin stayed pale and white but the rest of her gained new markings, and what remained of her elongating hands and feet turned dark. 

The glow began to leave her skin from tail to head, new marks stopped shining and revealed silvery sleek fur, her cries emerged as guttural barks from a blubbery throat and the eyes were last, the blue glow faded from them leaving behind dark black orbs.

She dropped to the floor a new creature; no longer remotely human, but still a mammal, an absolutely massive, wailing, leopard seal.

John was shocked by a jolt of his own, he hadn’t even noticed he himself was hovering just barely off the floor until the power that held him there dropped him as well.

“That’s a spectacular backfire,” mumbled a lovely baritone behind him, and John turned to see Sherlock, lying naked as the day he was born on the grating and smiling at him. John wasted no time gathering Sherlock up in a tight hug, burying his nose in Sherlock’s neck, kissing his jaw, so so happy that it had worked, that destroying that old book had reversed whatever curse Jim had laid on him. 

“Oh Sherlock,” John murmured squeezing him a little tighter.

A harsh bark from Jim startled the pair away from each other if only for a moment. John helped Sherlock to his feet in order to get some distance from the flopping bulk of a seal as she continued to bark and whine. Inside the tank John noticed the form of a huge shark as well, tiger-like stripes visible as it surfaced. It hadn’t just been Jim and Sherlock, it had affected Sebbie as well, reverting her to her natural form.

“I get a feeling Mycroft is going to be cleaning up fish for a while,” Sherlock said, directing John to look down at the floor where at least a couple of sharks lay surrounded by the tatters of clothes.

John barked out a laugh. Maybe shouldn’t have been laughing, the sheer number of fish Jim might have had employed as people would mean a massive smelly mess when they couldn’t all be tossed in the water soon enough. But the whole situation, the craziness of it, the happiness that it was all finally over, having Sherlock back safe and sound, left him unable to do anything but giggle hysterically. Sherlock joined him after a moment, the pair leaning against each other as they looked down at the dead fish.

And then other people appeared, crawling from the other aquarium tanks nearby to stand wobbling against the railing. The agents who had been captured, and several more people emerged, looking around lost and confused.

“We should probably help them,” John said, once the giggling had died down, resting his head on Sherlock’s shoulder.

“Mm, yes,” Sherlock agreed leaning his head on John’s with a sigh.

“Your gills are gone,” John remarked quietly, hand finding Sherlock’s and meshing their fingers together, “and the webbing.”

“As are yours,” Sherlock replied squeezing John’s hand back to emphasize the lack of webbing there.

“We’re human again,” John said with a smile, pecking a kiss onto Sherlock’s shoulder.

“We were always human John,” Sherlock corrected, pressing a kiss into John’s hair.

“Except when we were massive fish,” John replied.

“Mm, no, even then still humans, just cursed with extremely unusual circumstances.”

“Fine we were still human… God I’m just glad it’s all over, never want to set foot in water ever again.” John said, watching as the dazed agents helped each other up and began regaining their bearings, looking for their missing equipment.

“I would hope you’ll still bathe,” Sherlock replied with a small chuckle.

“Maybe, if you come with me.” He leaned up and laid a kiss below Sherlock’s ear.

Sherlock grinned and pulled John even closer, “Perhaps, that can be arranged.” He said, finally giving John a full kiss on the lips.

The moment was interrupted by a loud splash nearby and they both looked to see Jim’s tail disappearing into the water of the tank, joining the tiger shark.

John moved away from the railing leading Sherlock towards the scaffolding stairs to see the pair under water. For a Moment he had thought Sebbie would revert to simple shark instincts and tear into the blubbery mammal entering her tank, but instead the pair simply circled around each other. Jim, the more flexible of the two, clung close to Sebbie’s sides, hugging her fins and butting her whiskered face into Sebbie’s rough hide. Still a strangely loving pair even in this form.

“I would have liked to know what was in that book,” Sherlock said, watching the couple beyond the glass.

“You might be able to, the pieces are probably still up there.” John nodded his head towards the grating above them.

John watched the gears turn in Sherlock’s head for a moment, that infinitely curious intelligent mind contemplating the remains of the book warring with the urge to stay at John’s side after their ordeal.

“Go on, I’ll be right here when you’re done,” John said, helping him come to a decision. 

With a last thankful kiss to John’s forehead Sherlock darted back up the stairs, John chuckling at his lover’s retreating naked arse. Sherlock was not gone long; he returned moments later with a disappointed frown on his face.

“It’s gone, nothing left, not even a scrap of the cover,” Sherlock pouted, throwing his arms around John to bring him back into a hug with his chin resting on John’s head.

“Guess it’ll just have to remain a mystery,” John replied, hugging Sherlock back. He was perfectly fine with not knowing what that book held, all he wanted was to go home with Sherlock and be warm and not anywhere near an aquarium for quite some time.

Over Sherlock’s shoulder he could see the grey light of dawn glowing through the corrugated plastic windows, and John hugged him even tighter, happy in the fact that they’d see the sun, that they’d never become tuna fish ever again.

  
  


**Notes for the Chapter:**

> Thank you so much for reading this silly strange fic. I know I took a bunch of artistic liberties, and it was so cool to actually get to visit the Sea Life London Aquarium (also I hear there's been a bit of filming for Sherlock done there, which is even cooler to me. :D ) 
> 
> Thank you readers all so much.


	9. So Long and Thanks For All the Fish

**Notes for the Chapter:**

> Thank you Nautilicious for betaing this chapter for me, it took a while to get this fic done, thanks for sticking with me.

“Jemma ‘Jim’ Moriarty,” Mycroft said, looking on as the massive tranquilized leopard seal was being hefted into a transport container. “And her bodyguard.” His gaze roamed over to the larger tiger shark angrily still circling the confines of her too-small tank. “It is safe to say you will not be hearing from either of them again,” he said, turning to John and Sherlock, who stood wrapped in matching grey, wooly, first aid blankets.

The agents, after a few moments of disorientation, had provided Sherlock with the means to call his brother. In total there had been fifteen other people who had emerged from the water after Jim’s spellbook had met its demise at John’s hands. A handful of them had needed some friendly coaxing by John to leave the water, a number of them embarrassed by their nudity or simply afraid to come out. A couple more had been in their fish state for so long they had trouble returning to land and using their regained legs.

John and a couple of agents had made woeful attempts at trying to get at least a few of the sharks scattered about the warehouse into water, only managing to get two of the smaller ones in. The rest were simply too heavy and there was not enough time. The warehouse was beginning to smell faintly of rotting fish by the time Mycroft and his team arrived, the light of day already showing through the dirty plastic windows.

“What will you do with them?” John asked, looking up at Sebbie’s tank.

“Seeing as neither can be properly housed in a captive situation long term,” Mycroft paused regarding Sebbie for a moment as though he were contemplating the few options for the huge shark. “They’ll be fitted with tracking devices and released into their respective habitats. Fiji for the shark, maybe somewhere near Rothera Station in Antarctica for the seal.”

“You’re just going to release them into the wild?” John asked skeptically. Off the top of his head he could think of a few ways that could go spectacularly wrong, not least of which would be if they decided to venture towards civilization and attack people.

“They _will_ be monitored,” Mycroft replied sternly, as though surveillance alone would keep the pair of dangerous animals in check. John sighed, not willing to argue with him about it; he would be glad to just never have to see or hear from the horrible pair for the rest of his life.

“Oh Sherlock!” The elderly woman immediately wrapped Sherlock up in a hug. “I thought I might never see you again, what with Mycroft coming by and his ‘secret missions’ in ‘far away countries’ without so much as a note left or any idea of when you might be coming back!” She babbled into his coat’s lapels as he gently returned the hug and awkwardly patted her on the shoulder until she finally let go with a small sniffle.

“Well I’m home now, Mrs Hudson, and look, you have a new tenant as well,” Sherlock said, a faint edge of fondness in his voice as he tried to pass her focus off onto John.

John noticed how she looked at Sherlock in a motherly way, looking up at him like Sherlock was a lost boy who’d finally come home with his only excuse being ‘I was off catching tadpoles and suddenly it was night time,’ but she did finally turn to John. 

“Hello-”

“John, Dr John Watson, I’ve been, er, helping Sherlock,” John introduced himself to her, fumbling for words as he tried to not mention the aquarium while talking about how they’d met. 

“Oh!” Mrs Hudson’s face lit up at that, all smiles as she forwent the usual handshake and went right for a light hug. John glanced at Sherlock over her shoulder and Sherlock simply shrugged the silent ‘she does that’ plain on his face. “Sherlock’s found himself a colleague, has he? Well come in, come in.”

She ushered the both of them inside to the small foyer. Sherlock made an attempt at going up the stairs, but she stopped him with a hand on his coat sleeve and a gentle word about how he looked skinny as a rail. With that she managed to loop them into having a bite to eat in her parlor. John sat and munched happily on the biscuits and nibbles and tea she provided while Sherlock kept glancing at the door after the first bit of offered food. 

“Will you be needing the spare room upstairs, Dr Watson?” Mrs Hudson asked, a knowing glimmer in her eye. 

“Oh, uh, no, that’ll be fine, Sherlock and I-”

“Ooooh you _are_ a couple, Sherlock, congratulations dear.” She tittered happily.

“Yes Mrs Hudson, John is my--”

“Partner,” John interjected, watching Sherlock’s eyes suddenly dart to him with a questioning glance of ‘what is the word for us?’

“--Lover,” Sherlock said at the same time, both of their mouths snapping shut as they looked to one another. John watched a light blush start to rise on Sherlock’s cheeks and felt a matching warmth rise on his own face. Mrs Hudson simply looked pleased at the pair.

“On that note, Mrs Hudson, I think it’s time we retire upstairs.” Sherlock motioned towards the ceiling with a feigned a yawn, trying to get out of the mild awkwardness that they had landed in.

“But you just got home,” Mrs Hudson said, not falling for the minor theatrics.

“Actually I would like to see the flat,” John agreed, following Sherlock to stand. While Sherlock’s yawn had been fake, it inspired a real one from him and made John realize just how tired he was after their long night of insanity. The wounds he’d sustained may have been healed in the final transformation but their effects were still felt, lumped in with the sheer exhaustion of staying up all night and well into the morning.

Sherlock moved over and bent to give Mrs Hudson a hug and light peck on the cheek, “We’ll just be upstairs,” he said, going back to John and moving him towards the door and the stairs beyond.

Seventeen steps and through a door that was quickly shut behind them and John found himself in a very homey if a bit messy sitting room. He didn’t have time to focus on the be-headphoned cow skull on the wall, the stacks of papers everywhere, or the pair of chairs by the fireplace; John was quickly being snogged within an inch of his life and was not even remotely going to try to stop it. Sherlock had a hand on John’s face and the other snaked around his waist, pulling him in even closer.

“What have I done to merit that?” John said when they finally separated, a little breathless but no less happy for the attention. 

“Without you, John, I… We wouldn’t be here, we’d still be stuck in that godforsaken fish tank,” Sherlock replied, quickly kissing him again before trailing lips across John’s cheek and burying his face in his neck. John chuckled as that soft mouth set about sucking at a spot there where once gills had been in the way.

Another yawn interrupted any response John had to that and Sherlock’s face reappeared in front of him with an arched eyebrow. “Sorry, love, just it's been such a long night,” John felt that slight blush rising again, here Sherlock was being all lovey and John was nodding off. The eyebrow went down though and Sherlock’s face softened again into a small smile. 

“I could give you a short tour,” he said, nodding at the room behind him. “And maybe a long nap is in order?” Sherlock added, giving John a sweet peck on the cheek.

“That sounds good.” John pecked him back and Sherlock straightened up. 

“Well then, you’ve seen the sitting room now.”

“And it looks a bit of a disaster,” John added, eyes roaming over the somewhat organized chaos of piles that littered the room.

Sherlock shot him a worried glance. “I can fix that.”

“Later,” John reassured, turning into the connecting kitchen which was its own unique brand of messy. Laboratory equipment was strewn across nearly every flat surface, with a microscope sitting dead center.

“The kitchen,” Sherlock said, trying to shuffle past him and block John’s view at the same time, leading him towards the hallway past the refrigerator. “The bathroom.” Sherlock pushed the door open a bit to see a thankfully clean bathroom, all in a minty green and white.

John followed him down the hall, amused by Sherlock’s small pang of self-consciousness over the state of the flat. Assuming he’d had time for the ‘proper wooing’ bit of his plan Sherlock probably would have had the flat cleaned up, but John didn’t really care about the mess. If anything he prefered to see it, because it was Sherlock. John knew Sherlock had his oddities, veering between absolute chaos and ridiculously neat when the mood struck. No point in trying to hide it now.

“And our bedroom,” John said, following Sherlock into the room at the end of the hallway and seeing a large neatly made bed dominating the room.

“There is one upstairs if you feel you need it,” Sherlock said as he pulled off his coat and hung it on the back of the door.

“Why would I need it?” 

“We have been forced into close quarters with each other for an extended period of time-”

“Let me stop you right there,” John interrupted. “I wasn’t forced to be with you at the aquarium. If I had wanted to I could have completely avoided you and stayed in other areas of the building. Hell, I probably could have turned into a fish in one of the other tanks, too. I chose to stay near you. I enjoy being with you, and if all the spectacular snogging and shagging we’ve been doing hasn’t helped reinforce that in that thick skull of yours I’m not sure what will.”

Sherlock didn’t have a response for that right away. He just stood there for a moment looking at John, like he was analyzing whether John was telling the truth. “So… Our bedroom,” he finally said.

John smiled and moved over to peck Sherlock on the cheek again. “Ours,” he said, pulling off his jacket and tossing it onto the small chair in the corner. “Now then, you wouldn’t happen to have something I could sleep in?”

“Besides nothing at all?” Sherlock replied with a sly grin.

“Ha ha, you may enjoy being in the buff 24/7 but when sleeping I like clothing. Altogether too much nudity in the last 24 hours,” John groused as he undid the buttons of his shirt.

Sherlock hummed an assent and went to the chest of drawers against the wall, pulling out a couple of pairs of neatly folded and rolled pyjama bottoms. They undressed the rest of the way in silence, both stripping and each donning a pair of bottoms. They didn’t fit John well, being too long in the legs, but they were soft and comfortable and that was all that really mattered.

“Do you have a side?” John asked as Sherlock turned down the sheets. A quick look from John to the bed and back said ‘no.’

“Should I?” he asked, eyes widening as though John had just asked him something life-threateningly important that he hadn’t thought of before. 

“No, just curious, you won’t mind if I sleep on the side with the lamp, then.” John couldn’t help but chuckle at Sherlock’s face.

They got situated just fine, with a little shifting and shimmying to get cozy, and there they were finally in a proper bed. John let out an almost obscene groan as he settled and relaxed into the softness of the pillows, it felt like it had been ages since he’d seen a bed. Sherlock rolled towards him and, as was his usual move, started winding around John, wrapping him up in arms and legs and spooning into him with a small kiss to the nape of his neck.

“Comfortable?” Sherlock asked with a small laugh that vibrated through John’s back and made him smile in return. 

“Very.” John pressed back into Sherlock and pulled one of his hands up to give the back a kiss, twining their fingers together. It may have been only about mid-day but Sherlock had drawn the curtains and made the room lovely and dim, perfect for falling asleep. John could already feel himself slipping towards it, the only thing keeping him awake now was a niggling thought that maybe Sherlock didn’t particularly want to sleep and John was forcing him to be there. 

“You’re not tired are you?” John mumbled quietly after a moment of silence.

“Not as much as you, no.” Sherlock replied just as quietly, nose brushing the back of John’s neck as he nuzzled infinitesimally closer.

“You don’t have to stay if you don’t wanna.” John made a lazy attempt to roll over and face Sherlock, but the man had him in his grip and didn’t let him go.

“I would like to stay, don’t want to leave you again for a while.” 

John grinned at that, finally letting himself drift towards sleep. “Okay.” 

The last thing he remembered before dozing off was Sherlock reaching out across him to tug at the lamp cord and draw them even further into darkness. He resettled and wrapped an arm around John’s waist again, kissing into his hair one more time, and John finally slept.

John woke struggling. For a brief moment he had no idea where he was, and the fact that his awakening wasn’t accompanied by the shrill tone of the little plastic watch as usual only reinforced that moment of terror because that could mean they overslept and could be about to transform. John’s eyes shot open immediately and the only thing keeping him from physically lurching from the bed was Sherlock’s arms wrapped around him and a leg thrown over both of his. 

It took a second for John’s brain to wake up properly and realize: there was no blue glow of aquarium tanks, no sound of water, no hard surfaces. He was in a soft bed, in a nice warm room, under a fluffy duvet, with Sherlock clinging to his back. The nightmare was over, no more fish and transformations. John took a deep calming breath and reached for Sherlock’s hand on his stomach, pulling it up and clutching it to his chest as he let the breath out again. Bed, he was in bed at Baker Street. 

Sherlock shifted behind him with a small hum, squeezing John slightly, like a cat stretching after a nap. John couldn’t help the a quiet laughter that escaped him as he felt Sherlock unconsciously grind his hips into John’s rear, a very stiff morning erection pushing into the curve of his lower back.

“Morning to you too,” John murmured, pushing back. The response drew a grunt from Sherlock. John waited patiently for his bedmate to become cognizant of his surroundings. The gentle huff of a silent yawn hit the back of his neck and the hand John was still holding to his chest gripped back.

“Morning?” Sherlock mumbled sleepily. John felt him sit up behind him and turned his head to look back at the dim figure of him in the orangey lamplight through the curtains. Sherlock looked around the room as though scanning it before he flopped back down and resumed cuddling into John’s back. “It’s not morning, it’s only just gone 10pm,” Sherlock said, sleep roughening his voice to something gravely and sexy that did things to John’s stomach. 

“Well, you’re still sporting some impressive morning wood there,” John replied with a mildly wicked chuckle, pushing his arse back into Sherlock’s hips.

“Ah,” Sherlock’s hips rolled into him again, as though they had a mind of their own, “It does have a poor sense of timing.” The dark chuckle that followed vibrated through John’s back and he felt it inside his own chest, the feeling making him bite his lip. “Would you like to help teach it some?” Sherlock whispered in John’s ear, the playfulness easily audible, making John grin at the corny line.

John turned over in Sherlock’s arms, still smiling, “You know I would,” he replied, bumping noses in an attempt to land a kiss. 

Sherlock’s belly jumped as John skimmed a hand down, barely hesitating at the elastic of his pyjamas before closing around Sherlock’s hard cock. They both gasped, lips so close together they shared the breath. Sherlock surged up into John’s fist with a lovely low whine, all John had to do for a long moment was hold his hand still as Sherlock fucked into his solid grip.

“Good?” John nearly purred, kissing the corner of Sherlock’s barely parted lips. The dry skin shifted easily over the hardened core of his cock, foreskin pulling back with every slow thrust. Just the feel of it made John harden as well, a warmth rapidly building low in his gut that made him begin to gently thrust into nothing. 

“Mmhmm,” was the hummed reply, even as his hips stuttered and he seemed to be trying to will the pleasurable movement to stop.

“Wrong position?” John asked lightly, holding still.

“Mmmhmm,” he hummed again, and an arm pulled John over with him as Sherlock rolled onto his back. John got the hint and let go for a moment to get situated between Sherlock’s knees. He sat there looking down at Sherlock in the barely-there light, the duvet a warm cape around his shoulders. 

John smoothed his hands up Sherlock’s body from crease of hip to swell of pectoral; taking a moment to tease nipples with thumbs and getting lost in the slight arch of Sherlock’s back into the small round and round motion, pad catching on the gradually hardening nub. He grinned, loving that Sherlock was so much more sensitive there than himself. He kept up the maddeningly hypnotic little movement, alternating sides, until Sherlock let out a groan.

“John,” and a pair of heels were digging into the small of his back, Sherlock circling him with his legs and pulling John forward. He reached out with long arms and captured his neck. John found himself hugged to Sherlock’s chest, face right at the perfect level to nip a collarbone. He received a huff and an almost impatient buck, quietly reminding him that there was a wonderfully hard cock inches from his own and waiting for some attention. John let him have it: he pushed forward and slotted their cocks together side by side in the warm space between them, shifting a palm down to provide some added pressure. Pressing Sherlock’s cock up into his own belly and pressing his own down right beside it made for some lovely friction.

The pair continued to undulate, thrusting slowly under the warm tent of covers. John sucked on Sherlock’s collarbone, leaving a mark for sure, not that Sherlock was complaining. It began to chafe though and John had to stop.

“We’re not slimy anymore.” John complained quietly into Sherlock’s throat when an impatient whine erupted there.

“Lube, top drawer, pick one,” Sherlock replied, unwrapping his arms from around John to let him up.

John chuckled at the nearly gasped instructions as Sherlock continued to try to move and rub beneath him. “In a rush are we? What happened to that sense of timing?” John asked, opening the drawer and finding a small selection of bottles to choose from alongside a new-looking box of condoms. He picked the one that looked most used and sat back on his heels as Sherlock let out a louder groan and threw an arm over his eyes.

“Drama queen,” John huffed, popping the cap and smearing the slick on his palm. He took Sherlock in hand and pulled with one long, slow, draw, gathering as much foreskin around the barely leaking glans as he could then doing the same going down, revealing the flushed crown again. Sherlock’s mouth dropped open at the much smoother contact and the intensity of the strokes, arm still in place over his eyes. His hips came off the bed following that first glide.

John kneaded Sherlock’s balls, pressing firmly behind them to get Sherlock gasping some more. After the initial flurry, Sherlock began to melt into a groaning puddle of pleasure, John massaging his testicles, playing gently with glans and foreskin, thumbing at the frenulum, externally pressing for prostate. John loved reducing Sherlock to this, all soft and warm and vulnerable.

“Want some more?” he asked, leaning forward to nose under Sherlock’s wrist and plant a kiss on a cheek, trailing down towards his ear and kissing below there.

“Yes,” came a deep rumbling answer, voice sounding just short of wrecked, hitching slightly when John gently tugged at his balls again.

John paused, considering what to do next. He kept the rhythmic strokes going. He could finish Sherlock off like this, speed up the strokes, ratchet the pleasure through the roof and make Sherlock’s come stripe his stomach. But, he’d done that before, he knew how to make Sherlock come quick and dirty. John wanted to do something different. After all, he realized, this was their first night at Baker Street, properly home, with proper lube, and a proper bed. He kissed the nearby earlobe as he considered something he hadn’t done yet with Sherlock.

“Want me to fuck you?” John asked quietly, sitting back to see Sherlock’s response. The arm lifted away to reveal pupil darkened blue eyes staring at him. “Or not, I can think of a couple other ways to christen our bed,” John added, taking his hands away from Sherlock’s penis and putting them on his thighs, calmly stroking through the sparse hair there.

“ _Christen the bed_?” Sherlock suddenly snorted a laugh. “Yes, let's.” He continued to giggle, making John’s smile grow while he grabbed more lube for his fingers. 

“Relax for me,” John said, hooking an arm under one of Sherlock’s knees and pushing it up towards Sherlock’s chest, exposing him a little better. Sherlock’s deep chuckles continued at the tiny bit of manhandling, his other knee drawing up as well. 

Sherlock was nice and relaxed. The sounds from him hitched and turned into a groan at the initial breach. The hot clench of him only served to make John’s arousal flare, he’d been so focused on pleasuring Sherlock that he’d nearly forgotten about himself. He pressed upwards into that heat and with doctorly precision rubbed right over Sherlock’s prostate. 

That first forceful rub caused Sherlock to be the most vocal John had heard yet, a sharp gasping cry bursting out as his back arched, arse pushing down into fingers for more. John smirked and continued the stretching, rotating between slow stretching and tormenting Sherlock’s prostate even as he worked up to two fingers, which were better able to massage it with, and then three.

Sherlock was writhing on John’s fingers at three, a thumb pressed to the perineum and three fingers stretching him open. John had had to pause multiple times, backing off as Sherlock babbled at him that he was about to come when John had manipulated his prostate a little too much. On one hand it’d made John smile and just want to finish him off, make that slight dribble at the end of Sherlock’s hard, twitching cock turn into a torrential ejaculation; but on the other hand they were working towards something more, and John absolutely did want to fuck him tonight. So he backed off a little, staving off Sherlock’s release some more, making that husky baritone moan and beg. “Please, John please,” he plead at the ceiling, his breath coming in harsh pants. 

John pushed inwards with his hand at the same time he leaned forward to capture Sherlock’s lips, nearly folding him in half with the knee that had managed to find its way over John’s shoulder. “Ready?” he asked teasingly, curling fingers hard inside, stroking inner walls, and making Sherlock writhe a little more.

“ _John, please._ ” He’d effectively turned Sherlock’s brain to mush, all intelligent words out the window, sacrificed momentarily to the sheer amount of pleasure John was piling on top of him. He withdrew, leaving Sherlock for a moment a pleading mess as he reached for a condom and quickly rolled it on. 

Gripping Sherlock’s hips, John pressed up against him, blunt head of his cock barely prodding. “Sherlock,” John brought those pale eyes back to focus on him, kissing a nearby knee as he ran a hand soothingly up and down the other thigh.

“Mmmm, come on John,” Sherlock moaned trying to shift a bit and only causing John’s cock to slip back down between his arse cheeks. John huffed a laugh and took himself in hand, guiding the head back to Sherlock’s anus and finally pressing inward.

John watched Sherlock as he pushed, one long smooth thrust, lube doing its job fantastically. Sherlock stilled at the initial breach, John saw his chest stop as he held his breath and brought a hand up to stroke Sherlock’s breastbone. “Breathe,” he said quietly with a little smirk, even as the furnace that was Sherlock’s body seemed to pull him in deeper to the hilt. Sherlock let in one long breath and let it out with a content sigh, seeming to relax even further into the pillows with that one exhalation.

Once buried John stilled, for both of their sakes, letting Sherlock adjust and keeping himself from going off instantly. “Okay?” John wanted this to be good for Sherlock and so far it seemed so; coming instantly felt like it would ruin the moment. Sherlock reached up and curled a hand around the back of John’s head, carding fingers through his hair as blown pupils gazed up at him. “Move,” he demanded a heel slipping up behind John and digging gently into his lower back.

John immediately drew back and repeated that slow glide in again, and again, and again, taking up a leisurely pace at first as he drove into him, pulling out till the crown just barely tugged at the rim and pushing back to the hilt. Sherlock’s fingers dug into John’s scalp at the initial thrusts, hand sliding down to grip the back of John’s neck as though he were trying to pull John down to him. John went and Sherlock crushed their lips together.

John lamented the lack of gills only here, missing the fact that he hadn’t needed to surface for air before, they could have stayed locked at the lips gills working the air for them. But alas, John had to breathe he separated and sat up again. 

Sherlock groaned, “faster.” John obliged, snapping his hips forward harder.

But this time the position wasn’t quite working for John; he couldn’t get the angle he wanted, all the aches of the day felt like they were catching up to him again, and his knees were beginning to burn. It wasn’t long before John was disengaging, Sherlock letting out a unhappy groan.

“One moment, here, come here,” John said, thinking back to the first time Sherlock had fucked him and how good this position had felt for him. He laid down next to Sherlock, condom clad cock still standing hard and thick in the air, and grabbed Sherlock, getting him into position above him. “There, now you control the speed,” John explained as Sherlock gazed down at him, the moment it took to reposition bringing back some of the sharpness to his eyes.

“Making me work now?” Sherlock asked, all in good humor. He sat back and impaled himself on John’s penis, sinking with a long, satisfied moan.

“Not in the slightest,” John replied, grinning up at him as he gripped onto Sherlock’s waist and held him still as he fucked hard upwards into him, giving him that ‘faster’ he’d wanted before.

It was as though he’d hit Sherlock’s vocal switch as nearly every thrust seemed to pull more happy noises from Sherlock’s open mouth. John had surprised him with the sudden onslaught, hammering right up into Sherlock’s prostate. Sherlock’s hands, which had been braced, one on John’s knee the other on the bed, went to John’s on his waist, long fingers trying to pry John’s away. Sherlock threaded their fingers together and started to rock himself, arse meeting John’s thrusts with a short litany of oh’s.

At first Sherlock didn’t seem to know what to do with their Joined hands, his lust addled brain not making it much farther than ‘fuck back = more pleasure!’ He seemed conflicted about whether to lean back and let John’s thick cock pound into his prostate or lean forward and kiss John. The gears in his brain had slowed to the point John could nearly see the decision click into place and Sherlock surged forward, taking their joined hands from their place atop Sherlock’s thighs and pinning them on either side of John’s head, claiming his lips in a biting kiss, plush lips sucking at John’s. 

“Come on... come for me,” John said, as Sherlock panted into his neck, having traveled down and sealed his lips there, sucking at thin, gill-less skin. John wrestled a hand from Sherlock’s grip and dove between them with it, capturing Sherlock’s dripping cock and matching his pace both internally and externally. 

Sherlock’s back arched sharply with a cry into his neck at the extra stimulation. Still bouncing on John’s cock, he was caught off guard by his own sudden orgasm. “J-John!” His body locked up in the throes of passion, hand gripping John’s hard, internal muscles tightening up, John felt Sherlock’s breaths coming in harsh ragged pants from his nose against his shoulder as everything seized for a moment of extreme pleasure.

John watched enraptured as Sherlock came across his stomach, white pulses surging sluggishly from him to cover John’s hand after the initial spurts. And John didn’t let up, continuing to milk him with slow tugs and powerful thrusts. He wanted his own orgasm now, wanted to follow Sherlock over the edge. Sherlock was coming down from his, slumping astride his lap, but John was still going, thighs burning with the strain of maintaining the driving pace with the almost dead weight of Sherlock in his lap. Sherlock clenched around him trying to help him achieve his goal, a hand fumbled back to feel behind him and John felt those long fingers on either side of the place they were still connected, pressing at the underside of his cock as it disappeared and reappeared from that ring of muscle, it felt strangely incredible, and finally John felt the rush of orgasm, that high as he finally came inside Sherlock, thrusting hard a few more times between fingers and into that tight ring, clinging to Sherlock, before going limp, panting. 

“Fantastic,” John panted into Sherlock’s neck, gripping the hand that was still interwoven with his next to his head. “Gorgeous,” he added, kissing the closest bit of Sherlock his mouth could reach.

“Devolved to single adjectives have we?” Sherlock mumbled, not even trying to move yet and squashing John into the bed.

“Love you, gorgeous,” John murmured, wrestling his hand free from between them and landing it with a playful sticky smack to one of Sherlock’s arse cheeks, making Sherlock jump.

“Love you too, dear,” Sherlock chuckled, picking his head up and licking a wet stripe up John’s neck and ear.

“Ugh.” John pushed him off at that, trying helplessly to wipe the spit off. Sherlock rolled willingly over, John’s softened cock finally slipping free. 

They both lay there cooling down for a moment, quietly giggling at each other as the endorphins continued to course through their bodies. John made to sit up and bin the condom and suddenly felt a wave of dizziness come over him, making him flop back down next to Sherlock with a groan. 

Sherlock was on him in an instant. “What’s wrong?” he asked even as he seemed to list to the side himself.

“Overdid it, need a drink,” John chuckled weakly, moving to get up again a little slower this time. He padded off into the kitchen on wobbly legs to grab some water glasses. He didn’t expect Sherlock to follow him, but there he was, dragging the sheets with him like an oversized toga. 

“I was coming back,” John said, smiling as Sherlock took the sheet and engulfed him in it as well.

“You don’t know which glasses to use,” Sherlock mumbled into John’s hair.

“They’re glasses,” John said holding up the cups to the faint light coming through the window.

“I haven’t cleaned…” Sherlock drifted off to look across the pseudo-laboratory setting that was the kitchen. “Here, let me.” He took the glasses from John and found a different pair, handing one to John and taking a deep drink of the other with a sigh.

“Might have to show me around some more if we’re worrying about safe drinking glasses,” John snickered, taking a long drink of cool water and copying Sherlock’s contentment. 

“Too used to being in and around water,” Sherlock said, leaning into John’s back and wrapping his arms around his middle once he was done with his water.

“Hmm, maybe,” John replied, still sipping his, enjoying Sherlock’s post-coital clingy side. They stood there leaning against each other for a little longer until Sherlock suddenly separated from John, taking the lovely warm sheets with him. Sherlock knelt next to the door and picked something up.

“What is it?” John asked setting his glass down and following him the handful of steps.

“Mycroft,” Sherlock grumbled.

“Dear god, do you think he was here while we were-”John’s mind jumped to the horrifying thought of Sherlock’s brother listening to them go at it.

“No, probably slipped it under the door while we were asleep.” Sherlock cut John’s thought short thankfully, holding up a large yellow envelope. He popped the tabs open on it and slid out its contents, one photograph. “Oh, for God’s sake.” John saw Sherlock’s eyes roll and took the picture from him before it could be flung across the room.

It was one photo, of the inside of one large aquarium tank, featuring two massive fish who happened to be swimming near the glass. John immediately recognized Sherlock’s large tuna fish form with a mixed pang of humor, affection, and horror.

“It’s you,” John said glancing at Sherlock.

“And you,” Sherlock replied, resuming his position at John’s back with his chin hooked over his shoulder. 

“Oh? Where am I?” John asked looking in the background to see if Sherlock had spotted him there.

“That’s you next to me John, don’t be dim.” Sherlock grumbled a finger stabbing at the second fish in the shot.

“Oh,” John suddenly realized that he had honestly never seen himself in fish form. Sherlock had described it a couple of times, even mentioned that he was fairly handsome for a fish, but he’d never had the opportunity to see it. Staring at the pair of them in the picture, they did look quite nice together. A part of John’s mind supplied the aquarium might now be a little disappointed to have lost a pair of fine specimens such as themselves, the rest of his mind promptly stomped that thought to death. He never wanted to return to that building again, no matter how nice they might have looked. “Well, aren’t we a pair.”

“I’d rather not be reminded.” Sherlock didn’t sound remotely happy.

“Aw, I love you too,” John replied trying to lighten Sherlock’s mood before it went any darker.

“You know what I mean,” Sherlock said, burying his face in John’s neck.

“Yes I do,” John admitted. “I’ll keep this stored somewhere, we’ll look at it in a year or two and laugh then.” He turned the photo over to check if there was anything written on the back, but all there was was a yellow sticky note that read ‘congratulations,’ (for what John wasn’t sure, _congrats you aren’t a fish man anymore?_ ) And ‘the shark and seal have been taken care of’ which John had to guess was meant to be reassuring.

“Let’s go back to bed,” Sherlock said, taking the photo out of John’s hand and putting it on the table. He led John back towards the bedroom where he promptly flopped them both down on the bed, bundled John in sheets, and covered them in the warm duvet.

“We’re not going to change again,” John reminded him as Sherlock cuddled closer, burying his nose in John’s hair.

“I know that,” Sherlock replied, a petulant tone to his voice.

“You’re worried it will happen though,” John said, wrapping his arms around Sherlock and hugging him back.

“No,” Sherlock replied unconvincingly. “It is idiotic to think that we would transform again after spending a whole day not in that state.” 

“Well, I’ll be here for you in the morning when you wake up anyway, absolutely human, no fish here,” John said, rubbing Sherlock’s back calmly.

They lay there for a long moment in silence, just breathing and holding each other. “That’s what woke you up earlier,” Sherlock said, breaking the quiet.

“Yeah, thought we’d overslept,” John replied.

“Well, I’ll be here when you wake up again, no fish here either.” Sherlock said copying John’s promise, and making him chuckle at the silliness of it coming out of Sherlock’s mouth.

“Good.” And with that they both went quiet again, eventually dozing off back to sleep.

If Sherlock ever felt John startle awake again in the morning he never said anything, just hugged him closer, just as John did when he felt Sherlock startle. The first few days after that at 221B came with a slight adjustment period and that was one of them, becoming used to the fact that waking up in the morning and seeing the sun did not mean that they were about to die. They each had their own unique nightmares about the whole ordeal but they comforted each other when the nightmares woke them. 

John did as he’d said and stashed the picture of them together as tuna, pressed it in a book and put it away on the shelves in the sitting room. They didn’t need the reminder sitting framed anywhere or anything like that. Sherlock started getting cases coming in again, and John went running after him on those as well. 

And so the pair of them readjusted to life after the Aquarium. Sex was had frequently, Mrs Hudson definitely caught them snogging a few times. John accompanied Sherlock to crime scenes, and met the Lestrade he’d heard about from Sherlock’s other cases. Mycroft checked in on them infrequently, much to Sherlock’s annoyance. They stayed the hell away from the county hall building and the aquarium that lived on beneath it as much as possible. But most importantly John stayed with Sherlock, they loved and lived on and let the memory of the circumstances they met become just that, memories. 

And if Sherlock now and then got a text alert with an update about the status and location of the seal that was Jim and the shark that was Sebbie, he quite pointedly ignored it, and never ever mentioned it to John.

**Notes for the Chapter:**

> And That is the end. 
> 
> Thank all you readers so very much for giving this fic a chance, for all the kudos, and the nice comments. If you're ever in London I do recommend visiting the Sea Life London Aquarium, it is right next to the London Eye in a kinda touristy space, but its such a nice aquarium. :D
> 
> There will be a one-shot sequel featuring Leopard Seal!Jim and Tiger Shark!Sebbie. I can't say exactly when I will get around to writing it, but it is in the works.
> 
> Thank you all again so so much for reading this silly fishy fic.

**Author's Note:**

> Comments and Kudos are always enjoyed. :D


End file.
